Climate Justice Forum: Answering Earth’s Call

“We are hope gathering.” — Rev. Beth Johnson


gathered in the courtyard - IMG_0034-crop

The courtyard was filled with energy.

So many people came. The courtyard of St. Paul’s at Fifth and Nutmeg reverberated with their energy. They crowded into the Great Hall. People of many faiths and affiliations were gathered together, encouraged and challenged by Pope Francis’s courage, taking in and giving out the hope he inspires in us.

Pope Francis, as perhaps no one else could, is making the world see that climate change is a moral issue: a matter of justice for the poor, the vulnerable, and the children, who have done least to cause climate change and will suffer the most from it.


People crowded into the Great Hall.

Responding to Francis’s moral challenge, SanDiego350 joined with representatives of four great faiths, as well as other advocates for justice and the environment, in an Interfaith Forum on Climate Justice. The Forum took place last Thursday night, September 24, the day of Pope Francis’s historic speech to Congress. More than 300 people attended. [Read more…]

In Deep: Sea-Level Rise and San Diego

As we burn more fossil fuels, and thus pump more heat-trapping greenhouse gases into the atmosphere, we are changing every aspect of earth’s climate system. One of the many consequences is that the sea is rising.

On January 19, San Diego 350 will stage a simple action to help make people more aware of what rising seas mean to San Diego right now, as well as in the future. We’re going to Mission Bay, which is pretty much ground-zero for sea-level rise in our county, to mark out where the high-water line is likely to be in about thirty years. Come join us. It’s pretty striking where that line will be.

This page will give you some of the background on why this action is important. We’ll fill you in on what is causing the sea to rise, how it is likely to rise over time, and why it matters to us in San Diego.

Why the sea is rising.The sea is rising now because [1,2,3] water expands as it warms, like the mercury in a thermometer. It is also rising because higher temperatures are melting glaciers worldwide. Even the great Greenland and West Antarctic ice sheets are beginning, gradually, but possibly inexorably, to melt and slide into the sea. The world’s average sea level has already risen about eight inches since the start of the Industrial Revolution [1,2,3]. How far and how fast it rises in the future depends on how much fossil fuel we continue to burn and how rapidly the great ice sheets respond to the warming climate. Though both of these factors are hard to predict [1,2,3], one recent estimate is that global average sea level is likely to rise 12 to 18 inches by 2050, and 36 to 55 inches by 2100 [4]. It could rise 30 or 40 feet over the next few centuries, if the Greenland [3,5] and West Antarctic [6] ice sheets collapse.

Here and now. Though 12 to 18 inches over a few decades might not seem like much, sea-level rise is something we need to deal with, right here in San Diego. The map below, from a report by the San Diego Foundation [7], shows what even a little sea-level rise can do to a low-lying area such as Mission Beach. By 2050, roughly half of Mission Beach will likely be flooded at high tide. Much of the rest would be flooded about once in five years, when higher sea levels, high tides and waves from big storms combine.

Sea-level rise will flood Mission Beach by 2050

Rising seas will likely flood much of San Diego’s Mission Beach by 2050. The area in purple would be flooded at high tide. The area in blue would be flooded about once in five years, when storm-driven waves come on top of rising seas and high tide. (Source: San Diego Foundation/California Climate Change Center.)

That flooding is going to cost San Diegans real money. Our quick check of real-estate listings suggests that property in Mission Beach costs about $20 Million to $40 Million per acre. At those prices, the property within the five-year flooded area on the map below is worth roughly $1 to 2 Billion. That estimate is very crude, of course, but it does indicate that sea-level rise can have real economic consequences.

2050 is only thirty-five years away. That’s about the length of a typical mortgage. It’s well within the time-scale on which we make plans for our lives, including our plans for financial security. If your financial planning includes property in Mission Beach, sea-level rise is something you need to think about, right now.

More than flooding. The rising sea will do more than flood property. It will exacerbate the loss of beaches that we are already suffering [8]. It will shrink what little is left of our coastal wetlands [9,10]. Those wetlands are nurseries for fish and shellfish, vital habitat for endangered birds and other wildlife, and natural filters for the polluted runoff from our streets [11,12].

Rising seas will also increase coastal erosion [13,14], which is already a problem in many San Diego communities such as Solana Beach [15], Carlsbad, Encinitas and others. California as a whole could lose 41 square miles of land to the sea by 2100 [16]. That’s equivalent to erasing a strip of land 200 feet wide along our entire 1100-mile coast. However, the actual erosion would be concentrated in certain areas, so the loss in those places would be even greater.

Too much of the wrong kind of water. One of San Diego’s biggest rising-sea problems is happening hundreds of miles away, in the San Francisco Bay Delta.

The Delta is a vast, low-lying maze of channels, fed by the San Joaquin and Sacramento Rivers and emptying into San Francisco Bay [17,18]. Much of Southern California’s water [17,18], including 20 to 30 % of San Diego’s [19], is pumped from a collection point in the Delta.

Jones-Levee-Break-berkeley-coutesy dwr

Sea-level rise increases the risk of a severe levee break in the San Francisco Bay Delta, which could shut down much of Southern California’s water supply for months. (Photo: CA Dept. of Water Resources.)

The problem is that the water level in the channels needs to stay a certain distance above sea level, to keep out the salt water that tries to push its way in from the Bay [18,20]. Yet, the reclaimed ground between the channels has sunk as much as 15 feet below sea level [17]. The water in the system is precariously kept above sea level by 1100 miles of aging levees. If those levees break at the wrong place, the water in the channels will drop, sea water will flood into the channels from the Bay, and the water supply for 25 million Californians [18] will be ruined for weeks or months [20]. As the sea rises, the water level in the Delta, and the pressure on those rotting levees, must increase. Sea-level rise is thus one of several factors that are making this vital water system unsustainable [18,20].

Our governor has advocated a possible fix that would cost $23 Billion [21]. That’s $600 for every person in the state. In this sense, the rising sea is costing us all real money, no matter how far above sea level we live. Our perilous water system is one very concrete example of how we are connected in surprising ways to places far away, and how much our well being depends on public policy that recognizes the reality of our changing environment.

Beyond San Diego. Of course, sea-level rise affects far more than our city and our state. The United States has more than $1 Trillion worth of infrastructure at risk of going under water, with just a two-foot rise in sea level [2]. Many American cities are at increasing risk of flooding at high tide [22]. That risk is especially high on the East and Gulf Coasts. There, sea-level rise is compounded because the land is sinking and the slowdown of the Gulf Stream – itself a consequence of global warming – is pushing the sea upward along the shore [23] .

Sea-level rise increases hurricane flooding.

A foot or two of sea-level rise can greatly increase the area flooded in a hurricane. (Photo: NOAA)

In addition, in many America cities, a small rise in sea level can markedly increase the risks of flooding during severe storms. In San Francisco Bay, with sea levels just six inches higher, a relatively routine storm, such as might come along once a decade, could produce the same flooding that a much more severe, once-a-century storm would have produced before [24]. In Long Island Sound, a 19-inch rise in sea level would increase the property loss due to storm surge by 73% [25]. If the sea had been that high during Hurricane Sandy, coastal flooding losses would have been nearly $14 Billion. [26. See table, “The ten most significant flood events by National Flood Insurance payouts.”]

Along America’s Atlantic and Gulf coasts, more than 4 million homes worth more than $1 Trillion are at risk from hurricane storm-surge damage today. [26. See table, “Total potential residential exposure to hurricane storm-surge damage in coastal states.”] Higher sea levels will make this risk even greater. With so much investment at stake, rising seas are a very important factor in our nation’s economic security.

The future is now. The risks to Mission Bay, our Delta water system, and our nation’s infrastructure are examples of the very practical reasons why we need to mitigate climate change right now. But an even bigger reason is that our choices today will determine so much of the future, for such a long time to come.

Our responsibility to the future is spelled out by the physical processes that are causing the sea to rise. Those processes have several implications. First, the fossil fuels we burn today will affect the climate for hundreds or thousands of years, because the carbon dioxide we emit today will stay in the atmosphere that long [27,28,29]. Second, depending on how much carbon dioxide we allow to accumulate, the sea could rise by a tremendous amount over the next few hundred years: 23 feet if the Greenland ice sheet melted [5], another 15 feet if the West Antarctic ice sheet collapsed [6], even 70 feet if parts of the East Antarctic ice sheet collapsed as well [30]. Third, we are in deeper than we realize: As the heat slowly mixes down into the ocean and the ice sheets slide slowly downhill, the sea will continue to rise for centuries, just based on the greenhouse gases we have already emitted [3,5,6,31,32,33]. Yet, fourth, it is never too late to act: Although we have already caused a certain amount of sea-level rise that will unfold over time, we can always keep it from rising faster and farther by burning less fossil fuel [2,3,5,6,31,32,33].

Our action on January 19 is our effort to alert our fellow San Diegans to the reality of sea-level rise, its importance for us here and now, and the responsibility we have to every person who lives after us. We hope you will join us in Mission Beach, to see one small example of how real that responsibility is.


Thanks to George for his hard work researching sea-level rise, and to Bonnie for her thoughtful critique.

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Young Scientists: Hope from Climate Summit

“The world needs your voice. Use it.”


As a middle-aged scientist who wishes our society would make decisions based on reality, I get diNick & Kate from pdf 150 pctscouraged watching middle-aged politicians play power games while we keep burning coal and oil, pumping heat-trapping carbon into the atmosphere, and hurting our children. Sometimes, the only hope I can see is that younger people do seem to get the need to stop abusing our planet.

Two weeks ago, with my San Diego 350 colleagues Bonnie and Janina, I got to meet some young scientists who really do give me hope. As of my last post, these Scripps Oceanography and University of California scientists were headed to the world climate summit in Warsaw to make the politicians there a little less ignorant of what climate change is doing to our oceans.

They aimed high. At the conference, they gave two formal presentations, spoke with delegates from 70% of the countries represented and brought their messagOSIP & Figueres from pdf 150 pcte to top policy makers including the executive secretary of the United Nations body that governs the yearly climate negotiations.

Now, they’ve brought the climate summit back to San Diego, with a series of video and text blogs that you ought to see. My favorite is “COP 19: Who Cares?” a 5-minute video exploring whether summit delegates care about the oceans. The screen shots at the beginning and end of this post may give you a feeling for how lively and humanly engaged that video is. Their other postings offer interviews with climate protesters on the streets of Warsaw, testimony from summit delegates and ordinary Poles who care about climate, tutorials on how sea life is harmed by little-recognized changes in the ocean’s acidity and oxygen content, and eyewitness assessments of what really happened at the climate talks.

In spite of the dismal results of the climate negotiations, these young scientists came back inspired and determined to keep educating policy makers about the need to include the oceans in climate policy decisions. You can hear that determination in biological oceanographer Natalya Gallo’s blog post, “You Can Have an Impact – Scientists Informing Policy.”

Check them out: Ocean Scientists for Informed Policy. Their energy, hope and competence will give you strength to fight for our climate and our children.

OSIP photo spread from pdf 90pct

Photographs and video screen shots by permission of Ocean Scientists for Informed Policy. Blog post researched by Bill Avrin, Bonnie Funk and Janina Moretti.

Creative Commons License This text 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.


Young SD Scientists Alert Climate Summit to Ocean’s Plight

Young San Diego scientists at Warsaw climate summit. Left: Climate policy makers. Center: Scripps scientist Natalya Gallo alerts delegates to ocean’s loss of oxygen. Right: Educating policy makers at ocean science booth.

The world’s top climate-policy summit is going on right now in Warsaw, and many of the policy makers there know too little about the actual science of climate change. A dynamic group of young San Diego scientists is at the summit to do something about that. Two of them, Amy Van Cise from the Scripps Institution of Oceanography (SIO) and Nick Obradovich from the University of California (UCSD), found time to meet with a few of us from SD350 last week. We were so impressed, we had to let you know about them.

Amy Van Cise (Scripps Oceanography) and Nick Obradovich (UC San Diego) are among the young scientists aiming to bring science reality to the Warsaw climate summit.

Amy Van Cise (Scripps Insitution of Oceanography) and Nick Obradovich (UC San Diego) are among the young scientists aiming to bring science reality to the Warsaw climate summit.

The young scientists, mostly PhD students at SIO and UCSD, are focusing on a crucial area almost unknown to most policy makers: How global warming is affecting our oceans. The oceans cover more than 70% of our planet, absorb a quarter of the heat-trapping carbon dioxide that we are adding to the atmosphere, and take up 90% of the excess heat being trapped in the climate system. In that process, the oceans are warming, getting more acidic and losing dissolved oxygen. Those changes are  harming ecosystems, species and fisheries worldwide. Yet, the oceans are almost completely absent from the world’s policy discussions about climate change. The SIO/UCSD students are in Warsaw to bring key facts about ocean and climate to the 19th Conference of Parties (COP) to the United Nations Framework Convention on Climate Change.

Communicating ocean-science reality through formal presentations and informal connections.

Communicating ocean-science reality through formal presentations and informal connections.

It’s a tough audience to crack: An invitation-only conference open mostly to governments and big nongovernmental organizations. But, as part of the official Scripps/University of California delegation, the students have rare access to policy makers. They’re taking advantage of that access with an energy that surprised us. Through persistence and force of will, they’ve managed to get two full presentations included in one of the side events that go on at COP. (How they navigated the UN bureaucracy to get those talks included could make a blog posting in itself.) They’re also spreading the word through their booth, and simply by walking up to delegates at the conference, armed with a few carefully honed key messages.

What impressed us most was the drive, sincerity and competence of the young scientists themselves. One of us (Bill) knows how tough a science PhD can be, especially at a world-class institution such as SIO or UCSD. We’re amazed they have the energy left over to reach out to policy makers. If Americans in general could meet climate scientists like them, many would get a better sense for how real climate change is.

They call themselves Ocean Scientists for Informed Policy. You can see them in action here (click on the gallery on the right), here, here and here. Check them out. They’ll give you hope.

Blog post researched by SD350’s Bill Avrin, Bonnie Funk and Janina Moretti. Photos courtesy of Ocean Scientists for Informed Policy.

Creative Commons License This text 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.


Not Just for Tree Huggers

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.

Creative Commons License 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.


Comprehend the Consensus

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.

Creative Commons License 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.

No Need to Let Your Head Explode

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

Warming of the climate system is unequivocalMost 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, 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.

Creative Commons License 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.