Proceedings of the Standing Senate Committee on
Agriculture and Forestry
Issue 16 - Evidence - May 8, 2003
OTTAWA, Thursday, May 8, 2003
The Standing Senate Committee on Agriculture and Forestry met this day at 8:35 a.m. to examine the impact of climate change on Canada's agriculture, forests and rural communities and the potential adaptation options focusing on primary production, practices, technologies, ecosystems and other related areas.
Senator Donald H. Oliver (Chairman) in the Chair.
[English]
The Chairman: I call to order this session of the Standing Senate Committee on Agriculture and Forestry. By way of background, on October 22, 2002, the committee was authorized to examine the impact of climate change on Canada's agriculture, forests and rural communities and to study the potential adaptation options, focusing on primary production practices, technologies, ecosystems and other related areas.
Since October 21, this committee has held 30 meetings on the subject of climate change, focusing its attention on the impacts and adaptation on the agriculture and forestry sectors as well as on rural communities. The committee has heard from a total of 106 witnesses thus far and we have sat for 67 hours. Farmers, forestry workers, municipal officials, scientists, tourism operators, academics and others have told the committee of their personal experiences with climate change and how they are addressing the resulting problems and opportunities.
Today, we are honoured to conclude our initial hearings on climate change by hearing two officials from the Hadley Centre for Climate Prediction and Research in the United Kingdom. The Hadley Centre for Climate Prediction and Research, which is part of the Met Office, provides a focus in the United Kingdom for the scientists associated with climate change.
For 140 years, the Met Office has been the U.K.'s national weather service. Now they also provide services to other government departments and to a wide range of companies in commerce, industry and the media with TV weather.
I will introduce the members of the panel, Mr. Richard Betts, Senior Ecosystem Scientist, and Mr. Peter Cox, Head of Climate Chemistry and Ecosystems.
Welcome to the committee, gentlemen. Please proceed with your presentations.
Mr. Peter Cox, Head of Climate Chemistry and Ecosystems, Met Office, Hadley Centre for Climate Prediction and Research: I will give you a general introduction to the Hadley Centre's work, how it is organized and how it relates to the external community. Mr. Betts will speak specifically to impacts on ecosystems and feedback from ecosystems, particularly with some reference to the Canadian situation.
I will give this introduction to the work of the Hadley Centre with the assistance of slides. The first slide provides information on the basic background role of the Hadley Centre and the motivating science questions, which may be familiar to you. On the second slide, you will see some definitions of the Hadley Centre: It is the U.K. research centre into climate change and it is the climate research institute of the Met Office. The Met Office deals with meteorological forecasting and we benefit from being part of that. There is a synergy between what we do and weather forecasting, which I will come to later on.
The centre was built up over 10 years since it was opened in 1990. Now, we have a staff of about 110, approximately three quarters of whom are scientists and the remaining are information technology support staff for the major computing systems that we have.
The Hadley Centre is concerned with policy questions. On the third slide you will see the list of the scientific drivers. We are interested in trying to understand the processes that control climate and represented these in computer models with greater realism. We are talking about simulating and predicting climate change.
We also want to monitor how climate is changing. Obviously, we need to check our predictions. We also wish to diagnose the cause of those changes, which is called ``attribution.'' I will move on to the fourth slide. To diagnose those changes, we rely on hearing from the Met Office and so we are embedded in a research situation in which we have activities of relevance occurring in our organization. This includes ocean forecasting, observations, computer support, pollution modeling and basic atmospheric research. There are also external research programs. We are connected to the university research programs, although we do not share the same funding. That is through the Natural Environment Research Council in the U.K. specifically. We are also connected to the World Meteorological Association, which organizes various inter-comparisons between different climate models.
We are funded primarily by the U.K. Department for Environment, Food and Rural Affairs, DEFRA, which funds us to the tune of about 8 million pounds per annum. Much of that is spent on staff and super-computing resources. The Ministry of Defence, which owns the Met Office, also funds DEFRA for about 3.5 million pounds per year and we have a core customer group in the Met Office that contributes about 1 million pounds. We also receive funds from the European Commission in the form of projects, which currently amount to about 0.5 million pounds and it is growing. Overall, the program receives about 13 million pounds per annum and is still growing. It is big science to do these predictions and analyses.
On the seventh slide there is a graph showing how the Hadley Centre connects to the external community. We are basically prediction but we are driven by policy. That impacts the kinds of things that you are considering. Although we produce climate predictions, we are closely connected to the Intergovernmental Panel on Climate Change, IPCC, which has branches dealing with impacts and adaptation as well as climate change. We are also connected to the U.K. Climate Impact Program, UKCIP, which is external to the Hadley Centre but strongly driven by our outputs. The primary people to whom we deliver are UKCIP, the IPCC and DEFRA.
I will speak briefly to the motivating science questions. The four questions that we are trying to answer are interesting. The first one, how has the climate changed, is based on the observations to determine whether climate has changed in a significant way. The second question is, why has climate changed, which is the problem of attributing the causes of climate change. The third question, how much will climate change in the future, is dealt with using model projections. Mr. Betts will speak to the consequences of climate change.
How has climate changed? We are responsible in collaboration with one of the universities in the U.K. for maintaining the global database of temperatures on land and in the ocean. You may have seen the plot showing global temperatures going up by about .6 of a degree over the 20th century. The facts keep rolling in with regard to extreme temperatures. For example, the 1990s is the warmest decade on record and 1998 was the warmest year, although I understand that this year will probably be warmer because of El Niño. There definitely has been a change over the 20th century. This can also be put in context as the longer-term change in the Earth's climate, where reconstructions for things such as tree rings actually show a downward trend over the last 1000 years and then an abrupt warming in the context of historical change over the course of the last century. That is the context we are looking at. There has definitely been significant change. The critical question is, what caused it? Has it been naturally occurring or has it been because of human interference?
The reasons for climate change are many, of course. The climate varies naturally because of such things as the glacial cycle, which is a classic case in point; the radiation on the medium-term time-scale of decades to centuries; and there are changes in volcanic elements. As well, there are the human forces, which we are primarily concerned about in the Hadley Centre. Greenhouse gas emissions are the primary one but there are also sulphate aerosols, which have a tendency to cool the climate; increases in tropospheric ozone, which has an effect on climate as well as ecosystems and human health; and land use change.
Essentially, something quite significant has happened in climate modeling over the last few years. One key concern was that we could not reproduce exactly the record of warming as seen in the observations. That is not true now because there has been recognition that the 20th century signal of climate change is partly a consequence of natural processes. For example, there was a mid-century cooling of the climate system that does not look consistent with the greenhouse effect. That turns out to be due in part to volcanic eruptions and partly because of change in these other outputs. To be fair, in the past, climate models would have rejected these as insignificant but they have been significant in parts of the 20th century.
The problem with natural forces is that they cannot explain warming and it is only with the natural forces, particularly the greenhouse effect, that it is possible to explain the recent warming. When we put the two together, we have an understanding of this rather complicated pattern of time of warming through the 20th century. We have a tendency to warm initially and then cool in the mid-century followed by a rather rapid warming. The mid-century is a consequence of natural force elements but it seems more and more that the later warming is definitely due to the greenhouse effect.
We now have a situation where we can attribute, to some extent, the causes of observed climate change. The next thing that we will be asked is, what will happen in the future, which is a key thing for policy.
To do that, we have a multistage process. All modeling centres do this currently. We go to a socio-economic group of experts and ask them to come up with scenarios of future emissions and land-use change. We use that information to drive the model We then pass the climate change impacts on to a further group who deal with impact.
This is a disciplinary process. The IPCC is structured in this way with separate groups doing separate bits of the problem. More and more we are coupling the entire system together.
When you get the slides you will see that even from a single model like ours, there is a large range of possibilities. These are based largely on the future emission scenario, which is only known within a factor of two or three. That translates into large differences in climate change and, therefore, large differences in impacts.
An additional uncertainty comes from the complex system that we use to model processes. It is based in large part on how sensitive the climate is to carbon dioxide, for example. There is room for error.
We are getting to the stage now where the climate modeling community is recognizing that a single estimate will never be enough. One of the key frontiers is to develop theories from an ensemble of simulations, instead of doing one simulation with our best guess. We can never know that it is our best guess.
We plan to do many hundreds of simulations using internal model premises, including the way clouds varies with droplet concentration that are unknown. Within those ranges, we look at all the possibilities. It is only when we get to the stage where we have got a distribution function of possible futures that we can really look at assessing risk, and, therefore, giving good guidance to policy.
Already in the Hadley Centre we have gone from doing one simulation to doing 50 or 100 simulations with a similar model but different internal parameters, all of which are feasible. We are getting a range of possibilities. The idea is that we would weight those futures based on how well they reproduce the historical and current climate. Some of those sets of internal parameters or variants would turn out to be not very realistic because they do not like the current model. However, many of the variants will, possibly.
That is one of our priorities for future research. I will not talk about the other graphs. Perhaps we can come back to this. I will now either answer questions if you have any or pass over to Mr. Betts to talk about impacts.
The Chairman: Perhaps it would be best if we left the questions until after we have heard from Mr. Betts. Please proceed.
Mr. Richard Betts, Senior Ecosystem Scientist, Met Office, Hadley Centre for Climate Prediction and Research: Mr. Chair, could I confirm that you do not have any of the figures that we sent to you?
The Chairman: We have the document entitled ``Effects of Climate Change on the Biosphere.'' The first page says: ``1. Impacts of climate change, 2. Climate-carbon cycle feedbacks.''
Mr. Betts: Excellent. The first line is a summary of what I will talk about, which is the impacts of climate on aspects of biosphere. I will then describe how some of the changes in the biosphere under climate change may feedback on a climate change and have a further effect on each climate change. I will then talk specifically about the effects of forests on climate, and how this may be relevant in climate change ideation proposals.
Move to the next slide if you want to follow. We can think of two different impacts of climate change. There are impacts on the natural environment such as changes in sea-ice, natural ecosystems, river flows and sea-level rise. There are also impacts important for humans such as the yields of our crops, the availability of water for drinking, changes in disease spread, which may be sensitive to climate, and, also, the effects of flooding, drought and so on.
My third slide shows two different ways of looking at climate impact. On the left we have, perhaps, the more traditional method of studying climate impacts. Mr. Cox mentioned how climate change science is often different for different groups. One group will come up with a scenario dealing with emissions, and another group, such as ours, will do the physical type of modeling. A third group will take our model output and look at the impacts in terms of change in ecosystems, water resources and so on.
Some of those impacts may actually have further feedback effects on the climate. The right-hand side of my figure here shows the return of impacts back on climate change. Change in ecosystems may be further affecting climate change in the future.
We use both these approaches in our work. The one-way approach is technically easier and quicker. Often, we will use that approach to see whether significant impacts in a particular area do occur when the impacts are important. If we determine that they are important, we will put more effort into the more technically involved side of the work, including these as feedbacks within our climate system model, extending our physical model of the earth system to include changes. I will describe that later on.
The first piece of work I will talk about is our fast-track impact system funded by DEFRA, the Department for Environment, Food and Rural Affairs, which uses the one-way impacts approach where we use our physical model output and apply that to other models without feedbacks.
I have a few examples from those studies. The map of changing river flows is done with a hydrological model forced by changes in precipitation, based on our climate model. Focusing particularly on Canada, you can see that that suggests an increase in annual mean river flow by the 2080s, due to an increase there.
Another study is changes in crop need where we have run an agricultural model. It charts changes in temperature, humidity and so on from that model. Again, focusing on Canada, that suggests an increase in crop yield by the end of the 21st century.
However, I would stress that these figures are subject to considerable uncertainty. This would be our best guess at the present time, but we would not set a definite prediction of what will happen.
The Chairman: We have your document in black and white. There is no colour on this. You are talking about a change in crop yields by 2080. How do we read this for Canada for cereals, for instance?
Mr. Betts: Sorry, I did not hear the last part of your question.
The Chairman: On the left-hand side of the slide it says ``potential change in cereal yields.'' How do we read that? What will be the change for Canada in the yields for cereal crops grown in Canada?
Mr. Betts: That would be the third panel down. The change would be 0 to 2.5 per cent increase in yield for Canada. For reference, the U.S.A. has a 0 to 2.5 change in crop yield. This study suggests a decreasing crop yield in the U.S., but an increasing crop yield in Canada.
The Chairman: Is there any country in the world that would have better cereal yields than Canada in that period?
Mr. Betts: We do not have the absolute cereal yield. This shows the change in cereal yield. Some countries do have a larger change in cereal yield.
Northern China and Argentina have cereal-yield increases of around 10 per cent. Of course, you would need to know their present-day yield if you want to know which country would have the most cereal yield. We did not determine that. This is just the change in yield.
The other study I will briefly mention concerns the work we have done on the implications for human health. One of the areas we examined is the effect of climate change on malaria transmission, which depends largely on temperature.
The map here shows a change in the duration of the season for transmitting malaria. We do not see any significant changes encountered there, but large parts of the mid-latitudes do see an increase in the malaria transmission season, often going from 0 to 2 to 5 months. Therefore, we have potentially a greater risk of malaria spreading in a warmer climate.
Moving to the feedbacks side of the work, by way of introduction, this figure, entitled, ``Atmospheric CO2 Concentration (Mauna Loa Record),'' is the record of atmospheric CO2 measured from the 1950s to the present day. There has been the well-known rising CO2 over the last few decades, but on top of that is the wiggle up and down every year, which is caused by the uptake of carbon dioxide by vegetation in the northern hemisphere as it grows in the summer and then the release as it grows in the winter. The fact that there is more land in the northern hemisphere means there is more vegetation growing in the northern hemisphere side than in the southern hemisphere side. Carbon dioxide is taken up by vegetation and released every year, which shows that the world's vegetation can have a significant influence on atmospheric CO2.
To look at the potential for ecosystem feedbacks on climate change, we have included the feedback loops from ecosystems back to the physical climate. Moving to our figure entitled, ``Hadley Centre Coupled Climate-Carbon Cycle Model,'' in the centre we have what would be the traditional climate model, which is the model of the atmosphere and the oceans. Within that, we have additionally incorporated a model of the ocean carbon cycle and also the land carbon cycle, which means that vegetation can absorb carbon dioxide from the atmosphere as it grows and pump that down into the soil to increase the soil carbon store. Then that is returned back to the atmosphere through processes of decay.
If it were in balance, the carbon into the global ecosystem would equal the carbon out. However, we are shifting the balance because we are warming up the climate and putting more CO2 into the atmosphere. Our model includes the potential release of carbon from the ecosystems back to the atmosphere. We can model the actual rising of CO2 in the carbon model itself, rather than prescribing it from some scenario of CO2 rise produced by some external study. As Mr. Cox mentioned earlier, that is the usual approach. Now we can actually calculate our own CO2 rise within the model, taking account of changes in lead systems.
My slide entitled, ``Changes in Tree Cover,'' shows the assimilation of changes in tree cover across the world from the present day to 2050 and 2080. You will not see the colours here actually, but what these results suggest is that the boreal forests expand northwards and also become thicker; because of the warmer climate and the rise in CO2. Vegetation will be more productive.
In the Amazon, our current model suggests that it will become much drier there and that will cause the forest to die back, therefore, there will be a release of carbon from the Amazon forest. Although extra carbon is taken up in the boreal forest, more is released by the Amazon forest in this simulation.
My slide entitled, ``Change in Global Soil and Vegetation Carbon,'' shows the changes in the soil carbon stores from 1850 to the present day, and then onwards up to 2100 in our carbon simulation. The line on the top of the right-hand bend is the changing vegetation carbon. There is an increase in vegetation carbon at first, because of increased CO2 in the atmosphere, which enhances plant growth and photosynthesis, and more carbon is taken up in the vegetation. However, after 2050 or so, the loss of forest cover in the Amazon means a lot of the world's vegetation carbon is returned to the atmosphere, due to the drying out of the Amazon, therefore, the global total of vegetation carbon has got to reduce again.
The other line shows the changes in soil carbon. Again, this increases at first because the more productive vegetation is dropping more leaf litter, thereby increasing the carbon uptake in the soil. However, that modeling includes the effects of temperature and moisture on the processes of decay in the soil. Higher temperature means more decay in the soil and a greater return of carbon to the atmosphere — so we lose a lot of carbon from the soil again under climate warming.
If we move to the slide called, ``Atmospheric CO2 Concentrations,'' that gives two projections of the rise in CO2 due to single business-as-usual emissions scenarios. The lower line is what you would expect if you did not include these feedbacks in the system, in other words what is so far the standard IPCC approach. That was just the rise in CO2 concentration to around 750 parts-per-million by the end of the 21st century. The other line includes our extra feedbacks where the forests around the world are changing and the global stores are losing their carbon as well, so we get a more rapid rise in atmospheric CO2, as the ecosystem responses.
The following slide, Temperature Rise Over Land,'' translates that CO2 rise into the global warming. Again, the lower line is what we would expect if we did not include these feedbacks — a rise of about 5 degrees Celsius over the next 100 years on average over the global land. The other line is what we get when we include these carbon cycle feedbacks — more rapid warming, up to about 8 degrees Celsius by the end of the 21st century.
There are other physical feedbacks as well as the carbon cycle feedbacks. One important one is the change in the reflectivity of the surface of the earth over the oceans and the land. For example, snow and ice is bright and reflective. They reflect sunlight back into space for the cooling effect. However, if a warming climate means that the ice is melting in the Arctic, for example, as shown in this slide here, which suggests that September sea-ice by the 2080s may have all but disappeared, that would darken the sea surface further. Therefore, the map of global temperature changes show — you probably cannot see too well if you have not got the colour — a darker colour in the high latitude near the North Pole, in particular. That means the temperature rise is greater at high latitudes. This is because the loss of sea ice means that the sea is darker and will absorb more sunlight, so it has more warming than simply adjusted due to the greenhouse effect. You get a more rapid rise in temperature at high latitudes.
Vegetation also plays an important part in the darkening of the land surface. My photo is taken from our research aircraft over northern Finland. You can see areas of dark forest contrasting with white unforested and deforested land. The dark forest is absorbing more of the sun's radiation, whereas the white, snow-covered unforested land is reflecting it back to space. So the forest has a warming effect by absorbing the sunlight.
This has important implications for using forest plantations for climate change mitigation for the Kyoto Protocol. We have done a study where we compare the carbon uptake effect of carbon sequestration plantations, comparing that with this change in the surface reflectivity of the earth by afforestation.
My slide entitled, ``Carbon Sink Plantations,'' shows estimates of the potential for carbon sequestration, assuming there is an area of valuable afforestation. We are able to determine how much carbon would be taken up by the soils if forest were planted on unforested land. This is not a map of actual afforestation potential but it shows the potential for sequestration if the land were available for that. Such a scenario would also have implications for the change in surface reflectivity, or albedo. If open land were replaced with forests, the land surface would be darker and therefore less light reflective, thus, there would be an additional warming effect on the climate.
Moving to the next slide, we are able to compare these two terms, the carbon uptake and the surface reflectivity change, in terms of a quantity called ``radiative forcing,'' which is perturbation to the Earth's radiation budget — the amount of energy coming into or out of the planet. The top slide shows the change in the greenhouse radiative forcing, which would be due to carbon sequestration by these hypothetical afforestation plantations. The lower slide shows the radiative forcing in the sunlight part of the radiation wavelengths due to the darkening of the land surface.
Next, you will see a negative radiative forcing, which is a cooling effect. The carbon is taken up into the vegetation and reduces the rise in levels of carbon dioxide, CO2, and thus reduces the greenhouse effect. However, the positive radiative forcing, seen on the lower slide, indicates an extra warming effect. The key is: What is the overall radiative forcing? We can simply add up the data from these two maps to give the net effect of ``carbon sink'' plantations. In some areas of lower latitude, such as the U.S.A. or Western Europe, the overall net effect is still negative. The carbon uptake effect, which is the dominant effect on climate, would have a cooling effect. In other areas, such as Eastern Siberia and Eastern Canada, there is an overall warming effect, which means that the darkening of the land surface has a greater effect on the climate than has the uptake of CO2. It is not as simple as assuming that the carbon storage change reflects the change in climate. If you want to know the true effect on climate, you have to take into account the changes in the reflectivity of the land surfaces, which are complications for freezing forests where you have climate change.
Climate impacts research suggests increased river flow, crop yield and forest growth in Canada, but it is worth reiterating that those are subject to considerable uncertainties. Changes in global vegetation and soil carbon may act as a positive feedback on climate change, which could accelerate the climate warming. Again, that is subject to a variety of uncertainties.
Changes in the reflectivity of the land and sea surface because of melting snow and ice could increase warming at high latitudes. Forestry activities could have further effects on climate through changing the reflectivity of the land surface as well as through carbon sequestration.
The Chairman: I will begin the questioning with the committee's deputy chair, Senator Wiebe.
Senator Wiebe: Are your projections, especially those on page 11 and 12 of your presentation, based on mankind merrily continuing on with the spewing out of carbon into the atmosphere? Are they based on that human activity slowing down? Are they based on the targets that the Kyoto Protocol has set to bring us back to 1990?
Mr. Betts: Most of these projections are based on what used to be termed the ``business-as-usual scenario'' of the IPCC, and basically, do not include any response to climate change through policy.
Senator Wiebe: One could say that this is the worst possible scenario, if we were to do nothing. Is that correct?
Mr. Betts: Business as usual might assume that it could not get any worse.
Mr. Cox: Perhaps I could interject. That was a relatively old scenario. The latest scenario uses the latest IPCC report, which has a much broader change. There are predictions that are much more pessimistic with regard to continuing emissions. That is a kind of central estimate, if you like.
Senator Wiebe: For my own information, could you explain how our oceans absorb, maintain and release carbon?
Mr. Cox: Perhaps I could do that. Essentially, there are two sets of processes. One is that CO2 just dissolves in water and it tends to dissolve in colder waters. Carbon dioxide is absorbed in the higher latitudes, such as the North Atlantic, where it sinks with the cold-water to depth. Typically, it will bubble out at the equator so you get a kind of the circulation through the system. The second thing that happens is marine biology is involved. Organisms take up carbon dioxide and phytoplankton at the bottom of the food chain. They are consumed and that produces debris falling to depth, which is called the biological pump. Both activities seem to be important to future climate change, which has an impact on those processes. For example, there is a tendency, when you warm the ocean surface under climate change, to stabilize the ocean such that there is less mixing. That can have two effects. It tends to reduce CO2 going to cold- water depth and it can reduce the amount of nutrients that are available to marine biology. There is a general tendency, even with the ocean, for climate change to tend to suppress the uptake of carbon dioxide by the ocean.
Senator Day: I did not follow well the effect of afforestation and the darkening of the surface in Canada. It seems that the effects in Eastern Canada are different than in Western Canada. Could you explain the effects to us?
Mr. Betts: That is right. The darkening of the surface depends largely on the length of the snow season. The darkening of the surface is greater when the underlying surface is covered in snow. In warmer regions, such as British Columbia, the surface darkening is not so great because there is not as much snow cover. In the colder parts of Canada, there is snow for a longer period of time during the year and so the surface is darkened much more. The overall effect is a net warming effect in Eastern Canada but a net cooling effect in Western Canada.
Senator Day: I have a couple of other points for clarification. When the soil is heated due to climate change, would that have the effect of releasing some carbon dioxide from the soil? Is that a natural phenomenon due to the heating or is there a chemical or physical activity that results in the CO2 being released?
Mr. Betts: It is the change in the activity of the microbes of the soil. This process is subject to considerable uncertainty. There is much controversy about the actual response of the out-going carbon fluxes to changes in temperature. Overall, there is widespread agreement that the rate of release would double with every 10-degree rise in temperature.
Senator Day: You referred to the Amazon forest area and the net negative effect of forest disappearing with an increase in temperature. There would be a positive effect in relation to warming. Could you tell me, is that the result of not having the trees to take the carbon dioxide out of the air, or, is that a result of the slow deterioration of the trees and a release of the carbon from those decaying trees?
Mr. Betts: It is both actually. You need the forest air to take up more carbon in the future, but also the air there is released.
Mr. Cox: It is both. It is primarily the fact that you are releasing a lot of carbon that is currently stored there. You are losing not only the vegetation carbon but also the soil carbon underneath it. Obviously, when you stop putting the litter in, the soil will be consumed and turned into CO2 by microbes. You do lose some sink, but mainly you use much stored carbon in the system.
Senator Gustafson: My question is around the impact of what is happening. This committee has been told that the rocky ice pack is depleting, and the northern polar is warming up. One indication was that within ten years it will be possible for ice breakers to move boats through the northern passage on a constant basis, instead of going around to the Panama Canal.
I find that people are interested in how it will impact them. Have you any comments on that?
Mr. Betts: We did not specifically apply our attentions to that kind of question. What you say is right. The models would suggest less sea ice and greater freedom to move around the northern landmasses like that.
Mr. Cox: That is true. One of the pictures that you probably got in the handout shows the sea-ice extent. It is about half-way through Mr. Betts's presentation. You can see that formerly blocked shipping routes are opened up, but many other things happen as well such as permafrost melt, which has structure and other implications for northern latitudes and effects on the ecosystem. Part of the problem is that the changes are likely to be so fast that adaptation of ecosystems will be difficult.
Senator Gustafson: What about sea levels?
Mr. Cox: Sea levels are a long-term commitment thing because it takes a long time for the heat to penetrate the ocean. It primarily must travel the expanse of the ocean. Even if you stopped emissions, you would be seeing a rise for many hundreds of years.
There are some things in the climate system where we are committed to adapting. We cannot mitigate against some level of sea level rise that will be significant, but we can determine ultimately the rate and the extent.
Other things in the climate system that are faster can be mitigated against. You are not forced to adapt if you mitigate. Sea-level rise is something to which we are committed to a significant extent.
Senator Gustafson: I gather from your presentation that Canada will have a net benefit from global warming. Am I assuming that correctly?
Mr. Cox: It is difficult to say that. Some of the natural resources likely will increase. If you warm the high latitudes, which will happen, you might expect extended growing seasons, and you might expect the hydrological cycling — evaporation-precipitation cycle — to increase, meaning more rainfall.
You might also expect problems associated with that. The same thing will happen in the U.K. You might expect more flooding or extremes. That is true in Canada. I do not see why it would not be. You will get an increase in the mean availability of resources but also more extremes, I would say.
Mr. Betts: Our models are still incomplete in terms of representing the earth's system. There are many processes that we do not have in there. For example, we do not have changes in insect attack on crops and forests, or changes in fire activity in the forests. Our model shows an increase in the growth of boreal forests but did not include change in fire activity.
This is where we are at the moment. There is more to do before we are truly representing everything that may happen in the climate system.
Senator Gustafson: You indicated that Canada may have the warmest year on record. Apparently, we had the coldest February on record.
Mr. Cox: That can happen. The more regional you look, the more variability there is in the climate. It is possible that one region could have the coldest season, but it would still be the warmest year globally. These figures are global ones. As you get to the regional scale, you are talking about highly fluctuating quantities. It is always difficult.
Senator Gustafson: Thank you for an interesting presentation.
Senator Lapointe: Gentlemen, I am a substitute on this committee today, and I am happy that I came because I have learned many things of which I was not aware.
Perhaps my question will sound absurd to you. Not so long ago, I read an article that mentioned that the Amazon forest was the lungs of the Earth. What happened? Why is that not the situation any more?
Mr. Cox: It still is to some extent. As far as the water cycle is concerned, the Amazon forest is critical. It is also important in the carbon cycle. It is possibly the most important region of the earth, but it is only one region.
We see in our model an impact on the global system as the result of the Amazon disappearing. The Amazon is critical to both water and carbon cycling, and you see that in our projections. It would be an absolute disaster if the Amazon were affected extensively by climate change in the way in which the modeling suggests. It is a great worry.
The Chairman: We are having this meeting with you today because the 106 witnesses that we have heard referred to your models. Your models are held up around the world as being pretty exceptional.
Why do you think that is? How are your models different from some of the other world models that are used in trying to determine the why and the how of climate change?
Do you collaborate with other research institutions and universities? Some of the professors we met in Canada said that what is really required to put a handle on adaptation strategies for climate change is many different disciplines working together. Do you collaborate with a number of other research institutes and universities?
Finally, I want to ask a technical question about your modeling. Witnesses have told the committee that the resolution of general circulation models is too large to clearly indicate the effects of climate change on agriculture and forest and help us give specific advice to these industries. What would be the adequate scale of a model that would allow a good understanding of the adaptation required by agriculture and the forest industry?
Mr. Cox: I will take the first two questions, and leave the third to Mr. Betts.
It is really pleasing that people think that we are doing a good job with the climate prediction and modeling. There are two reasons that that has been possible. First, we have had relatively stable long-term funding from the U.K. government.
The Chairman: Is that not interesting?
Mr. Cox: Get that one down. This program has been operating for more than ten years.
To develop this kind of model from scratch — which is what we did although building on previous work — you have to be patient and have long-term funding. We have had that and it continues. To develop the models that Mr. Betts showed, there was five years before we produced anything. On the typical climate, even in the U.K., on the typical grants that you get in the university sector, you might get only two or three years to do something. It is just not possible to do it. That is the first thing.
Second, we tend to have a cross-disciplinary approach.
It is true that you have to connect to the outside world and that is more and more the case. We have had people in the same building working on the biosphere components, the atmospheric aerosols, and the clouds — all aspects of the climate system in one building. In many other countries, first of all, there is more competition; there is not a single centre. Second, a lot of the expertise is external to the centre, which means you have communication problems sometimes.
To take your second question, how do we connect to the outside world, in some senses that is becoming a more and more critical thing for us? As we move away from the physical climate modeling system toward a broader system, where we are dealing with chemistry and biology, it is no longer possible to have all the expertise in the Hadley Centre. The way we connect with universities in the U.K. and around the world is key to that.
I suspect climate system modeling is going to become big science. The network of people feeding into your models is going to be critical. The models that will be most heavily used will be the ones that are best developed. The way we are doing that now is to set up collaboration initiatives with U.K. universities, where they are funding from their own funding sources and we are funding from ours, but we have collaborations that are mutually beneficial. We are doing likewise in Europe.
Mr. Betts: To take your third question about the resolution of climate models, the resolution of the global models, such as represented here, is sufficient to give guidance at large scales. If you want to look at smaller scales like, for example, within Europe or the U.K., we would use a high-resolution model.
What we would do is take a version of our global model and do a high-resolution version which covers, say, Europe, and mesh that within the global models, so the outside of the high-resolution model is forced by the output of the global model. Then we get the finer detail of the U.K. scale, for example, and that can be used for climate impact studies.
The other issue about actual predictions for the regional scale is that you are often held back by the ability to prove your model against the historical record. There is a lot of noise as you work through the internal variability of the climate system. The climate will change year to year anyway. That variability can be quite large in small scales.
So far, we have not been able to show a huge amount of scale for reproducing precipitation change of the 20th century in this kind of model. We cannot be confident in regional scale precipitation predictions for the next 100 years yet.
Senator Wiebe: Much of the effort that has been done by people in universities, research centres and different levels of government have concentrated on the effects of what is happening and the mitigation of those problems. Going back to Senator Lapointe's question, I get the feeling that we are not spending enough time and research money on adaptation. What happens when we lose the Amazon, for example? How will we adapt? In your mind, where are the gaps to adaptations and whose responsibility is it to provide the dollars and research in the medium and long term to address some of those adaptation problems?
From a farmer's perspective, climate change — global warming — will be a gradual concern and you can adapt as you go. In some of these other areas, it is far more difficult. Can you give us any idea if that is going to be a serious problem?
Mr. Cox: One of the issues is that, apart from a few things — like sea-level rise, which I mentioned earlier — the optimal strategies for whether you adapt or mitigate are not clear. With the Amazon dieback, if we could say categorically — and we cannot yet — if you avoid a carbon dioxide level of 500 parts per million, the Amazon lives, and if you do not, it dies, then the policy maker would have the ability to say there is a more likely probability. We are still in the process of assessing those dangerous climate changes.
How do we define it? Where does it occur? If you knew where those critical points were, you could make assessments about what you definitely need to mitigate against. However, you are right; adaptation will be necessary in lots of things, because we are committed, through things like sea level rise, to some degree of change.
The way that is dealt with in the U.K. is that we have a separate centre, called the Tyndall Centre, which is funded from the universities, which deals with mitigation and adaptation issues. It is fed data from our models. More and more, we are seeing that these things are linked together rather tightly.
What has happened in the past is that the scenarios of change, the scenarios of emission, have been independent of policy; and policy ultimately ought to be responding to the requirement to adapt or mitigate. We have not got there yet. We do not have the whole thing covered in the system.
Does that answer your question?
Senator Wiebe: No, but it is close.
Senator Gustafson: Have you done any studies on how climate change will impact world food supply?
Mr. Betts: Not as a whole. What we have done on crop yields was a first go at that, but you would need to look at the whole range of crops and livestock as well. That is in its early stages.
Mr. Cox: One of the things is that the impacts of climate change are extremely patchy. If you could see those maps in colour, you would see that there are some regions that benefit, some which lose. There is a tendency in the mid and high latitudes that the warming will not be detrimental to things like growing seasons. Where you really see the big impacts are in the developing world, where things are already pretty hot and dry. It looks like it might get worse. One of the biggest problems we may have with climate change is that there is an inequality in the way it strikes. The areas that are arguably the least responsible are the ones that are worst hit. That is a concern that needs attention.
The Chairman: In conclusion, you are the last witnesses that we are having in this study on adaptation to climate change. The researchers have already started to put a few words to paper.
One of the things that I would love to have your opinion on, when you do some of your modeling and research, and reach conclusions, what method do you use to communicate your results to policy makers, to industry groups, to farmers, foresters and other research institutions? How do you actually disseminate the results of your models?
Mr. Cox: Since we are funded largely by the U.K. government, we produce reports based on our contractual commitments that contain policy-relevant information. They will be partly responsible for distributing that. However, we also do other things such as public lectures. We do as many public lectures as we are asked to do with regard to the whole issue of climate change.
We often have presentations of things at conventions; the Hadley Centre will have some stand and will generally give some kind of presentation or outreach thing. We try to connect as much as we can to the external research community and the public at large for all sorts of things. Wherever there is a possibility to spread the word about climate change, we will do it.
The Chairman: Thank you very much. Your testimony has been very useful. We appreciate your efforts.
The committee adjourned.