Citizen’s Guides to Climate Change: How to Sort it All Out without Getting a PhD

This posting is the third in a series on how you can figure out what’s going on with climate change, without having to get a PhD in climatology and without going crazy from the conflicting messages in the media. My first post showed how you can bypass the media confusion by finding out what real scientists are saying. My second one showed how strongly scientists agree on the basic facts: Earth is warming. We’re causing it. The biggest contribution is burning fossil fuels, which accumulates heat-trapping gases such as carbon dioxide in the atmosphere. We need to burn less fossil fuel to keep the effects from getting too extreme.

In this post, I’d like to acquaint you with some of the people besides scientists who are concerned about climate change. Some of them may surprise you. Who they are and what issues they identify may give you a sense for why mitigating climate change is important for all of us.

It is no surprise that environmentalists call for climate action. If we continue increasing fossil fuel consumption, people who are small children today could experience, within their lifetimes, an increase in earth’s average surface temperature of 2 to 5 ºC (4 to 9 ºF), which is nearly as great as that between the last Ice Age and today. That rapid change would disrupt ecosystems all over the world. As warming exceeds 4 ºC, there is a risk of major extinctions, involving 40 to 70 % of the plants and animals assessed in the 2007 report of the Intergovernmental Panel on Climate Change. We can preserve much more of the natural world if we burn less fossil fuel and limit the warming to 2 ºC or so. Because extinct species are gone forever, the decisions we make over the next few decades will determine how much poorer a world we leave to every human generation that comes after us.

What you might not have guessed is that the American Academy of Pediatrics, American Medical Association, World Health Organization and other groups concerned with human health are also calling for action to minimize global warming and prepare healthcare systems to cope with it. These groups point out that climate change can affect people’s health in a variety of ways, including extreme heat and drought that hurt agriculture and increase malnutrition; injury and disease from more severe floods and hurricanes; water pollution due to flooding and drought; higher temperatures that worsen the chemistry of air pollution; and expanded ranges of pests that spread disease.

Another group taking climate change very seriously is the American military. Recent reports from the US Department of Defense and intelligence agencies have looked at climate change as a concrete threat to national security. Global warming brings more drought to places already too dry, more flooding to places already plagued by floods, and less food and water to people who already have too little, especially in parts of Africa, South Asia, the Middle East and the Caribbean where social tensions are high, governments are weak and resources for coping with disaster are lacking. In such places, the added climate stresses may exacerbate existing risks of violence and political instability. As the military describe it, global warming is a threat multiplier.

We have already seen violence exacerbated by the kinds of environmental stresses that climate change will increase. The genocide in Darfur, for example, may have happened in part because expanding deserts forced herders into land occupied by farmers with different tribal, ethnic and religious identities. Violence has also occurred in India between natives and migrants forced out of Bangladesh by flooding and rising sea levels. As global temperatures rise, the environmental stresses and the resulting conflicts will continue to increase.

Although the military have focused on climate change as a destabilizing force in poor countries, it is a very real problem for richer ones as well. The US Department of Agriculture has been looking at how global warming might affect food production in the United States. The effects they describe are complicated, difficult to project, and likely to vary by crop and by region. However, some of the most recent analyses indicate that, if fossil fuel burning increases as it could well do, corn and soybean yields in the US could fall by as much as 60 to 80% by the end of this century. The losses will be much less if we minimize the global temperature change by burning less fossil fuel.

As these crop-yield projections illustrate, radically changing the climate can have real economic consequences that are potentially serious but hard to predict. One group that knows about dealing with uncertain risks of economic loss is the insurance industry. Many leading insurers, noting the ongoing increase in the number and severity of weather disasters, have called for action to minimize climate change. Another leader in insurance, Lloyd’s of London, has looked at climate change from a broader business perspective. They start with the overwhelming scientific evidence for human-caused climate change. They then identify a number of consequences that could affect businesses worldwide:

• Water scarcity
• Food production not meeting demand
• Risks of mass migration from poor to rich countries
• Risks of increased international conflict and insecurity
• The increased unpredictability of a warmer world

The American Academy of Pediatrics, the Departments of Defense and Agriculture, and Lloyd’s of London are looking at climate change not as environmentalists, but because it is their job to assess risks and plan for them. Looking at the same science from somewhat different points of view, they each find that global warming presents significant challenges for our society.

A common thread in their analyses is that climate change can affect our lives in complex ways, with potentially big, but imperfectly known consequences. Climate change is about making choices in the face of imperfect information. Doctors, generals and insurance companies do that all the time. What we know for certain is that we have a real problem, and that the risks will increase as global temperatures rise. Our choice is how much risk we want to tolerate, and how quickly we are willing to reduce our consumption of fossil fuels. The more quickly we do that, the richer and more secure will be our world and the one we leave to our children.

This material by William F. Avrin is used here by permission of the author, and is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
 

 
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Citizen’s Guides to Climate Change: How to Sort it All Out without Getting a PhD

Scientists are telling us clearly that we’re changing the climate and need to do something about it. Yet, what we hear in the media can be so confused that many people feel they can never figure out what to think about climate change. If you feel that way, this posting is the second in a series on how you can get to the truth about the climate.

My first post showed how you can get started by finding out what actual scientists are saying, rather than trying to puzzle out the Al-Gore/talk-radio argument that the media sometimes make climate science seem to be. A good next step is to appreciate just how strongly and consistently scientists agree on the essential facts of climate change.

One expression of that consensus is in the statements on climate change by science organizations all over the world. Those organizations include the national science academies of at least 32 countries (links: 1,2,3,4,5). They include professional organizations in earth sciences (6,7,8,9,10), meteorology (11,12,13,14,15), physics, chemistry and biology. They also include the National Academy of Sciences, America’s foremost science advisory board, whose members serve without pay and are elected for distinguished achievement. These statements all affirm certain basic facts: The climate is changing. It is virtually certain that we are causing it. We need to burn less fossil fuel, to stop heat-trapping gases such as carbon dioxide from accumulating in our atmosphere.

A 2010 article in the Proceedings of the National Academy of Sciences took another approach to sizing up the scientific consensus: They counted. The authors identified the community of scientists who are most actively working on climate change, based on the number of peer-reviewed scientific papers each scientist had published, and how often those papers had been cited by others in the field. They looked at all the papers that those scientists had published. They then counted up how many of the scientists supported or challenged the basic understanding of human-caused climate change summarized in the Assessment Reports of the Intergovernmental Panel on Climate Change. They found that 97 to 98 percent of the scientists actually working on climate change supported that common scientific understanding. Other studies have found similar results. That nearly unanimous agreement among climate specialists, together with the supporting statements by national academies and professional organizations in related areas of science, indicates that scientists are in overwhelming agreement about the reality, human causes and urgency of climate change.

Another measure of how well settled the science of climate change is, is how consistent the scientists’ understanding has been over time. You can see that consistency in the very first Assessment Report of the Intergovernmental Panel on Climate Change. In that 1990 report, scientists reviewed the research up to that time, and summarized what we knew then about climate change. They identified most of the key points that you can see in the most recent Assessment Report from 2007. To list just a few of the biggest ones:

• Global warming happens because we are accumulating carbon dioxide and other heat-trapping gases in the atmosphere, mostly by burning fossil fuels such as coal and oil.
• We know the warming will happen both from the physics of the climate system and from geologic records that tell us about past climates.
• The details of how the climate changes depend on the behavior of clouds, snow, ice, water vapor, winds and ocean currents, which affect and are affected by the warming.
• We can see the warming trend in records from weather stations, satellites, balloons, buoys and other tools that measure land, sea and atmospheric temperatures, as well as sea level rise and the retreat of glaciers.

That warming trend was measurable by 1990, though the data weren’t yet strong enough to rule out natural fluctuations as the cause. By 2007, the trend was unmistakable, and the scientists estimated that there was less than a ten-percent chance that anything other than human causes could explain all their measurements of trends in different aspects of the climate. The main change in the science was that the understanding had gotten clearer, a few apparent anomalies had been resolved, and the evidence supporting the basic model had become even more massive.

These few sentences don’t nearly do justice to the amount of evidence that supports the scientific consensus. Indeed, one of the remarkable things about global-warming science is the sheer number of different ways in which the scientists have checked and cross-checked their understanding.  The National Research Council, an agency associated with the National Academy of Sciences, has a 40-page booklet that summarizes some of the many lines of evidence in language that non-scientists can understand. I hope to show you a few examples in future postings.

This posting’s bottom line is simple but crucial: You might not hear it on TV, but scientists have reached an overwhelming consensus that climate change is real, happening now, human-caused, and a problem we urgently need to deal with. Knowing that matters because, once people hear how strong the scientific agreement is, they are much more likely to agree that climate action now is one of our highest priorities.

This material by William F. Avrin is used here by permission of the author, and is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.

 Citizen’s Guides to Climate Change: How to Sort it Out Without Getting a PhD

“Warming of the climate system is unequivocal… Most of the observed increase in global average temperatures since the mid-20th century is very [90%] likely due to the observed increase in anthropogenic [human-caused] greenhouse gas concentrations.”

 Intergovernmental Panel on Climate Change, February, 2007

“If you want to know what’s causing global warming, listen to AM talk radio while watching ‘An Inconvenient Truth’ and simultaneously running a Google search. We’ll stand back and watch as your head explodes.”

Lenny Rudow, Boating Magazine, March, 2007

Scientists have a clear message for us: The climate is changing right now. We’re causing it. To keep the consequences from getting too bad, we need to burn less fossil fuel.

Yet, many of us aren’t hearing that message. Like Lenny Rudow from Boating Magazine, we just hear a loud argument between Al Gore and right-wing talk radio. We feel like we can never figure out who to believe. It’s easy to get that impression, because the voices of real climate scientists are barely audible in the media where most of us get our news.

You don’t have to feel like your head is going to explode. You can figure out what’s going on with climate change. You don’t need a PhD in climatology. You just need to know where to look, and sometimes a few common-sense tools for thinking about what you find.

I know, because I’ve been there. I’m a scientist, but not a climate scientist. I’ve been exploring ways to understand what science says about climate change for more than twenty years. In this and future postings headed “Citizen’s Guides to Climate Change,” I’d like to offer some sources, and ways of seeing, that have worked for me and may work for you.

A good first step is simply to find out what the scientists are actually saying. One of the most authoritative sources is the National Academy of Sciences, America’s foremost scientific advisory body. The Academy was founded by President Abraham Lincoln in 1863. Its members are elected based on their distinguished records of scientific research. They serve without pay. Their mission is to review what is known on scientific issues of importance to the country, and advise the rest of us on what that science says about the choices available to us. The Academy’s most recent review of climate change (also available in summary form) affirms the long-standing scientific consensus that climate change is human-caused, happening now and a real problem. Scientific societies all over the world have issued similar statements affirming that scientific consensus on climate change.

You should also know that there is a kind of master consensus document on climate-change science. Every several years, the Intergovernmental Panel on Climate Change brings together hundreds of scientists with expertise in every field that relates to climate. The scientists sift through thousands of peer-reviewed research papers. They assess what all that research is telling us. They send their work out for peer review by hundreds more scientists. Their Assessment Reports are pretty dense, but are our most comprehensive source for what we know about climate change, how well we know it, and what we need to know better.

Finally, if you’re a little technically inclined, you might check out realclimate.org, a blog maintained by working climate scientists for journalists and the public. Even if you don’t get all the details, you can get a sense for the thoughtfulness and depth with which real climate scientists think about the evidence. It’s a far cry from the shallowness – the thin-ness – of the bogus arguments we hear from climate denialists.

The take-home message is simple: Climate change is not about believing Al Gore versus talk radio. It’s a matter of solid science. If you know where to look, it is easy to find out what the real scientists are saying. They are sending us a clear message: We have a problem. It’s up to us to fix it.

This material by William F. Avrin is used here by permission of the author, and is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.