Communicating Impacts of Climate Change
Prof. Dr. Rik Leemans, Environmental Science Department, Wageningen University, Netherlands
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Because I am here to talk about the Millennium Assessment (MA), I changed the title of my presentation a little bit from “climate” to “environmental”. Climate is, of course, a major part of the environment. If you look at assessments, they are really a booming business, a lot of people are doing them, and they are not science, but communications. Here are some examples: The Dutch Concern for Tomorrow was one of the first in the late 1970s, the UNEP Global Environmental Outlook, the World Water Forum, the Arctic Climate Change Assessment, and the Dutch Sustainability Outlook. The Dutch Sustainability Outlook actually uses the IPCC scenarios, implements them for the Netherlands and then asks policy makers: What is your “business as usual” scenario? Compared to the policy makers, this assessment shows that the majority (i.e. 7050 of the public want a much more sustainable green scenario. That assessment really showed a big mismatch between the public and the ideas of policy makers.
What is an assessment? It is policy-relevant, in that you really try to translate scientific information to policy makers, but it is also a social process. When you work on these assessments you work as a team, you learn from other scientists, much of the time the teams are multidisciplinary. It is a process of involvement in bringing the findings of science to bear on the needs of policy makers. It is also about the monitoring networks you use for assessments, the data collected on a routine basis by national and international institutes. The assessments are translated to the users, and if you communicate successfully, you not only broadcast your message, also you receive. Communication is two-way by definition. If we forget about that and only broadcast, and never check whether a message is coming back, then something is wrong. This means you really have to listen to the policy makers, the stakeholders, the lay people, and then take their responses into your assessment when you set the agenda. It is a two-way process.
The official definition of an assessment is: “A judgement by experts based on existing knowledge to provide scientifically credible answers to policy-relevant questions”. This knowledge should be published in the scientific literature, and the IPCC has very stringent rules on that. Often people equate an assessment with a review of the literature, but it is not; a review is always biased, done by one author or a small team. Reviews never make uncertainty statements, or make them only rarely. However, uncertainty statements are actually essential in assessments.
Assessments also have to make a synthesis of what we know and value by reducing the complexity. Synthesis is essential, and in a scientific review syntheses are rarely done. The process is really trying to look at a whole field of knowledge, but communicating that to policy makers is difficult. When you start looking far in advance, say a hundred years, the average constituency term is only four years, so you have to create some kind of urgency. We can do that by using “doomsday scenarios”, there are different ways of doing that, but abstract theses will be criticized as unrealistic, so urgency is actually quite important. You also really have to speak with one voice.
We also have to look at risks, but risks are different for different people, and risk is a very difficult concept on which to agree. The IPCC conceptual framework is not only about climate, it is also about very strong socio-economic development power. What is happening? Are we going towards a much more sustainable world, with the Millennium Development Goals and low population growth, or will we have high population growth, high economic growth, etc.? Those different stories matter for setting the actual emission scenarios. If you reduce emissions, you are doing mitigation, solving the problem at the source. However, there will still be climate change, some of the change is inevitable, so you have to adapt to that and all its impacts. We can increase our resilience by raising dykes, for example in the Netherlands we are actually building floodplains and houses on boats, so when there is a flood they float up, when the flood is gone they float done, people are happy, they always have a waterfront view -- but that’s an adaptation.
Adaptation, however, has limits. The IPCC uses a lot of models, both simple models and very complex models, like the atmospheric general circulation model for the flows in the climate system, often linked to ocean models. The models are on the atmosphere, the biosphere, oceans, and society. Society enters into the integrated assessment models, and a big group was used to create the developing scenarios for a 300-page IPCC scenario book on how the world develops, which came out in 2001.
Since 2000, we have seen temperature increases and we have actually seen the first specific patterns in climate change. Once you have all the facts in mind, you have to look at what the policymakers want. They have made very strong statements and they still are making statements. At the climate convention, now about 15 years ago, in Rio de Janeiro, they adopted the climate convention, and set an objective: To stabilize greenhouse gas concentration in the atmosphere at the level that would prevent dangerous anthropogenic interference in the climate system. This is what policymakers want.
Scientifically it is very easy to say that stabilizing greenhouse gases will require a worldwide reduction of greenhouse gases of 50-60 %, adjusting for feedbacks really 70 % if we want to do it on the long term, and eventually we have to go to zero. However, it is more difficult to estimate what is dangerous, what constitutes risk. The climate convention has actually established some cases of what is considered dangerous, what the potential risks are: Ecosystems should naturally adapt to climate changes, food production should not be threatened by an increase in population, economic development should proceed at the same level. Now a richer population, or a wealthier population, will change its diet, people getting wealthier will actually eat more meat. However, you can feed half a person per hectare on beef compared to 20 persons per hectare on soybeans, and the resulting emissions will be dramatically different.
How do we actually use the assessments, how do we use the science to inform them? In principle, the notion of “dangerous” is a value judgement, as I have already said, and it is not appropriate for IPCC experts or scientists to determine what constitutes risk. Everybody has to do that for him or herself. However, we can provide scientific information to actually look at impacts and then decide.
At the IPCC we looked at different reasons for concern, trying to classify all the different information along a line. One of the important items was ecosystems impact. There are unique ecosystems that could be lost or damaged, such as coral reefs because of the acidification of the oceans and bleaching at higher temperatures, or polar bears because they don’t have ice to hunt on, or island states, etc., and some of these things are just too precious to lose, we really do value them. When we started looking at the literature, a lot of the impacts were done at the end of the century, projecting 3 to 4 degrees warming. What we want to know is the dangers of a half-degree, of one degree, etc., to get that ranking.
We therefore started looking at observed impacts, which were just starting to appear in the literature five to 10 years ago. At the moment there are thousands of papers claiming to see the impacts of climate change, everywhere people look they see the effects of climate change. One of the examples is actually Kilimanjaro, with a very big decrease in the glacial cover, partly because of global warming and partly because of local deforestation, which also creates some local feedback. If you still want to stand in the snow at the African equator, you probably have 10 years to save for the journey and to walk up there – after that, the ice is gone, along with four or five very unique tropical alpine ecosystems. That will be irreversible, because these systems are unique.
We see impacts in plants quite a bit. Oaks in the UK are seeding about a month earlier over a period of 15 years. A lot of caterpillars feed on those young leaves, and migrating birds feed on the caterpillars, it is a very nice system. However, now that the leaves are coming out earlier, the caterpillars are eating them earlier, but the birds are not coming back earlier from Africa. Previously, when they used to come back, they could wait two weeks before laying their eggs, and when the eggs hatched, the caterpillars were there. Now they arrive after having have flown about 3 000 km, these little female birds that weigh about five grams, and they see the caterpillars are already there, so they hurry to hatch an egg, but that takes time. As a result, the populations of some of the migratory species in the Netherlands has declined to a great extent.
So we are seeing quite strong changes already in the food chain. This is adaptation, an ecosystem response. However, we also see shifts in species. In the Netherlands we have been monitoring lichens on oaks throughout the country since the 1960s because of air pollution. Lichens are actually quite sensitive to air pollution, and lichen species are coming back now. Since the 1990s, a lot of Mediterranean lichen species are appearing in the Netherlands, and in the last five years even some tropical species. Lichen spores travel with the speed of a 747, there is no limit to their dispersal, so you see these species are one of the indications of climate change.
When assessing the observed changes, we were interested in risks, so we looked at the ecosystems and found that with no climate change there is little risk, with a little climate change some species (migratory species, alpine species, sensitive ones) are at risk, and at an increase of 2 degrees Celsius, risk really starts to increase. The communication was for scenarios of no risk, increasing risks, and dangerous risk.
A second reason for concern is extreme events: Heat waves, floods, a very small shift in the mean temperature can actually provoke a very rapid increase of extreme events, like floods as we have seen here in Prague. In the Netherlands this has also partly been induced by our changing land use, but flood intensity seems to be increasing, so a very similar type of reasoning applies there as well.
Another reason for concern was the distribution of impacts regionally. Negative impacts very much affect the global economy, and if we calculate the impacts in dollar values, or in Euros, you see that the rich people live in the areas that are less impacted, while many poor people live in areas that are strongly affected.
At the moment, we know much more about the impacts of extreme events and effects on ecosystems, and we have seen from the fourth assessment report, the Stern report, that if you compare the different models, you see clear patterns of drying inside areas that are becoming wetter. If you look at impacts, it is very likely that anthropogenic warming has a serial influence on many physical and biological systems. We have evidence from the oceans, from land, from all of the continents, that the climate is changing ecosystems. It is actually much more difficult to get evidence on human systems, because humans adapt. Dutch shopping streets five years ago had no air conditioning, but we had two hot summers with heat waves, so everybody has air conditioning now, and costumers are coming to the shops again. That is adaptation, and that is why people say climate change is not an issue, we have adapted. In society the impacts are actually much more diffuse.
However, 99 % of all the changes observed are consistent with the theory of what kind of changes we have to expect. The IPCC diagrams list the severity of the impacts according to the 1-2-3-4-5 degrees of warming scale. This helps you get a feel for what is expected, because if you look at ecosystems, for example, you can see that at one degree of warming there will be increased coral bleaching, most corals will bleach at two degrees, and widespread coral mortality will occur at three degrees.
In the fourth assessment report, communication on positive impacts, we saw that some of the forests are actually showing positive impact, partly because they are growing faster due to the higher concentration of CO2. We can expect to have more forests, and most of them will be young, sucking up carbon and storing it for us. What happens at the end of the century, we don’t know.
People respond differently to these reports. Blair called climate change one of the major challenges we face, while US Senator Imhoff, said climate change is a hoax. Imhoff is even stronger than the Czech president, and he was very strongly influenced by a scientist called Michael Crichton. Crichton claims he is a scientist, since he studied medicine, but you have to be careful with your definition of “scientist”, as he is actually a fiction writer, the man who wrote Jurassic Park, which is actually a book more to fear. In the Netherlands, the PM Balkenende said we really should adapt, we should make our country much more resilient for climate, and there was even a commentary in Nature called “Climate-proof in the Netherlands”.
The Stern report, the discussion with sceptics, is actually quite a difficult discussion, but the argument continues to shift, and one of the conclusions of the Stern report makes it clear that the issue is not the science, but other beliefs in the background. Some of the Dutch sceptics, whom I know quite well because we are always invited to television shows together, have taken a stance and built up a whole social life on debating climate change. If they were to actually start agreeing with climate change then they would no longer be invited to receptions, to meetings, or to radio shows anymore and their social life would collapse. This is probably one of the reasons they continue.
There is not only a Convention on Climate Change, but also a Convention on Biological Diversity, to conserve biodiversity, nature conservation, sustainable use of biodiversity and its components, and the fair sharing of the benefits. The Biodiversity Convention very strongly places North-South dialogue as its objective, on the use of ecosystems and the use of species, not just on nature conservation. They also did an assessment, the Millennium Ecosystem Assessment (I was responsible for one of its working groups), which really focused on linking the needs of people to ecosystems. We, for example, depend on ecosystems for the coffee we drink, the bread we eat, the clothes we wear.
In 2000 we really looked at the mistakes of the other conventions. If you want one of them to be used, you have to have political legitimacy; you have to listen to the users. What do you want, what is your agenda, how can we actually provide information? It is not about translating a scientific agenda into scientific information, but about two-way communication. You have to be scientifically credible, so you have to do the state-of-the-art assessment, and the utility for the users should be there. The Millennium Assessment (MA) looked at all the different conventions linking to ecosystems through a very strong stakeholder governance structure of all the different users (as opposed to IPCC, which is just governmental) and we used the IPCC procedures of peer review, etc. The MA was a little bit stronger, with more people from both the north and the south involved, and then we had an annual user inventory asking whether the needs of policy makers were changing (IPCC does that only every five years).
The MA looks at different ecosystems services: What do we use nature for? We use it for food, water, climate regulation, but also seas regulation and a lot of cultural aspects. People like to walk in the forest because it is nice to pick mushrooms, etc., there are a lot of experiences that link to people’s well-being. Doing these assessments is a social process where people are working together trying to convey information, to calculate the scenario, to look at the models, to discuss what text is. We had a conceptual framework with indirect drivers, on a very large scale, media drivers on land use, resource use, human wellbeing, and the whole system. For the MA it was done on a global scale, including a series of local assessments: What does it mean for local people? Those local assessments informed the global assessment again. This was also a way to include the indigenous knowledge of local people in the assessment. We spent a lot of attention in the MA on creating short-term “press release” kinds of messages. IPCC has never done that. The summary for policy makers is still 20 pages long, and then, on the last evening after two nights of discussion, the chairman wrote a press release.
The conclusions: There are humans who represent changes to ecosystems in the recent decade compared to earlier decades, and these changes have improved the lives of a billion people. The six and half billion people living now are better fed then the four billion living in the 1970s. There is still hunger, there are still inequalities, but we have made quite a bit of progress. However, this has come with a trade-off in terms of impacts on ecosystems, and if we continue, the impacts will increase globally.
I am still not sure if I am more proud about some of my papers in Science or Nature, which are widely cited, or of the fact that this part of my work became the topic of a cartoon in the Washington Post. I think the cartoon really conveys the message well, it came out immediately after the MA report: Evolution here is called “intelligent design”, and men are shown taking or scooping away one third of the world. This made a strong impression. A cartoon on the assessment process in The Australian then showed Mr Howard, who is probably not being re-elected next week, with Mr Bush, who will also not be re-elected next year, saying: “We need a scientific opinion. Fifteen hundred scientists can’t be right.”
The MA also got quite a lot of coverage in The Economist, 12 pages and five articles, which is extremely long for The Economist, which generally runs one to two-page articles. Science, Nature, and a lot of scientific journals covered it. We created graphs to show the trends of food availability, prices, and production, we produced maps showing the changes and tried to give a balanced view of the facts. For example, forests in the northern hemisphere are increasing rapidly, so deforestation is mainly a tropical problem. The net effects over the total forest areas have actually increased a little bit over the last decades, sucking up more carbon for us. There were links to climate and how land-use changes influence the climate system.
The scenarios of the MA were actually a big discussion and a step forward after the IPCC scenarios, where there was a focus on economic growth or sustainability. The MA was not one-dimensional, we can have economic growth and sustainability, there does not have to be a contrast between them. The MA did not look at the disparity between economic growth and sustainability, but focused on managing ecosystems services. What if we have pro-active management, foresee problems emerging, and act accordingly? With reactive management we only act when the problem and the risks are both very serious. The scenarios that came out show that there are strong regional blocks with very reactive policies; or techno-gardens, very much reactive policies with technical solutions; and then the somewhat more green scenarios in the middle. There were actually no models in place to do this - there were models on global ecosystems services, but no adequate models on biodiversity. So a lot of those scenarios were actually narratives and qualitative, in strong contrast to the IPCC work. Some of these models we used to illustrate the impacts of these scenarios, to see the ecosystem services. The scenarios show we can deal with the problem, very similar to the IPCC’s recent assessments; there is a problem with climate change, but we have the technological means and the economic means to actually deal with it. That is the main message of Working Group Three.
Of course to do this, you have to change your policy; you have to make major investments into environmentally sound technologies. There are choices, trade-offs with other areas. You have to take an adaptive management policy, pro-active action, take into consideration the public good, education and health. Strong actions are needed to reduce economic discrepancies and eliminate poverty. Poverty was seen as one of the major blocks to development. If you look at the differences between IPCC and MA, the MA had not only a global component, but also regional and local ones. IPCC was addressing one convention, while MA covered many conventions, intergovernmental or independent, funded through the IPCC and governments (there are a lot of funds - World Bank, Global Environmental Facility - and also private foundations).
One of the major differences, especially on the communication, was the governing structure. IPCC has an intergovernmental plenary meeting every five years to set the agenda, while MA has had a board meeting every year to set the agenda. If you do an assessment for five years and you can’t change anything, you are inflexible with the IPCC kind of structure; the MA was much more flexible. IPCC also did not build capacity, but the MA did. Students were signed up to different chapters and actually learned the trade. Thomas Hach from Charles University here in Prague worked with Bedrich Moldan developing one of the synthesis chapters. That kind of involvement of young researchers was actually essential to some of the outreach.
There were some interactions between the working groups. IPCC Working Group 1 designed a different way of communicating uncertainty than Working Group 2, there were disparities in jargon. “Tropics” means something different in WG1 than in WG2 – these are small things, but sometimes they make quite a difference for the conclusions, and because there were many interactions between the working groups, a lot of these issues were addressed in the MA. Model-based, qualitative scenarios were one of the major mistakes the MA made in contrast to the IPCC. The IPCC chapters were really team-building efforts, people came together, worked together and discussed the issues, you had to be together to actually learn each others’ opinion, while the MA had a meeting only of the invited lead authors and the other ones were just contacted by email. There was never a team-building to actually write that particular chapter, partly because of economic constraints.
In conclusion, I think assessments are extremely important to communicate complex scientific issues like biodiversity, ecosystems services, and climate change to policy makers. This is the only tool to actually take the whole width of the science, assess and synthesise it, and report it up comprehensively. However, they are not always effective, because they need a lot of effort. I calculated that the fourth IPCC report cost at least 200 million dollars. Most of the authors did their work voluntarily, but someone somewhere paid their salary. If you calculate the time involved, that’s the msin amount of the cost for these four reports. There is also a time lag. If you have to work on the scientific literature, publish scientific literature, before you can do the research and write the paper, then there is a year or two-year time lag to get work published in the journals, and then because of the review process, sometimes it is a three-year time lag in the IPCC report. For policy makers that is not very useful. If you communicate to a journalist, he wants to have the latest science, so you really take your latest results, and these can often be at odds with these assessments, because science also develops. A lot of the assessments are also quite inflexible in responding to policy needs. You have to set up the structures to actually do that. IPCC showed this was a problem in the early 1990s, but it was not dealt with. The MA developed its conclusions on the dependence of ecosystems, and both assessments showed this is not a “doomsday scenario” we cannot do anything about, but that there have been a lot of adequate responses. There are still a lot of negative points, however.
Dealing with uncertainty and communicating uncertainty, is extremely difficult in these assessments. They should, all of them, improve their responses to policy needs, because sometimes, such as during the last year, climate change comes on the agenda and things change very rapidly. We also need much more emphasis on developing a proper synthesis of the material.
We are trained as scientists to try to dissect things in a very analytical way. We are very bad at integration and synthesis, only a few people can do that satisfactorily. We are trying to train our scientists to do that at the moment, the environmental scientists, but it is still very difficult, and this is still one of the main constraints for successful assessments. Finally, there is a lot of time involved in each assessment. For example, when they asked me to chair one of the working groups of the MA, Bob Watson estimated it would take 50% of my time. But he is a workaholic, (he works about 100 hours a week) and the commitment was indeed 50% of that amount of time. So it is really almost a fulltime job. Being a lead author on an IPCC chapter takes three months just to write it, respond to reviews, etc. However, it is very rewarding, so if you get the opportunity to participate, do it!
Thank you very much.