Climate 411

On “Hackergate”: What the Stolen Emails Say About Climate Science

This post is by staff scientist Lisa Moore and EDF’s chief scientist, Steven Hamburg.

As you know by now, a few weeks ago, hackers stole over a decade’s worth of emails from the University of East Anglia’s Climate Research Unit (CRU). Climate change deniers cherry-picked a few phrases from those emails, took them completely out of context, and claimed that they disprove global warming. Nothing could be further from the truth.

There are already a lot of thorough responses to this manufactured non-scandal, including several RealClimate posts (e.g., here and here); a Nature editorial; statements from leading scientists and professional organizations such as the American Meteorological Society and the American Geophysical Union; an Associated Press analysis; a story in Time magazine; a Washington Post interview of a science historian; and (our favorite) a “Climate Denial Crock of the Week” video from Peter Sinclair, featuring Beavis and Butthead. Because the facts can’t be stated too many times, here’s our own response.

The data showing climate change are solid and overwhelming

The evidence for global warming comes from thousands of thermometer readings over many decades, analyzed independently by different research groups. CRU is one of four agencies that reports global temperature trends. Each of these four—NASA, NOAA, CRU, and the Japan Meteorological Agency (JMA)—works independently of the others to process raw temperature data. Even though they use different methods, all four agencies’ results show marked warming trends over the past several decades:

schelsinger figure

Figure by Dr. Michael Schlesinger, Univ. of Illinois, using results from all four agencies.

You can even do the analysis yourself since the raw data are available online. This sort of independent verification is a hallmark of scientific research. Scientists are always double-checking each other’s work to see if they can replicate the results. When multiple, independent researchers come to similar conclusions, it increases their confidence in their understanding of whatever is being studied. In this case, the data clearly show global warming.

And even beyond all this temperature data, the signs of global warming are everywhere:

  • Satellite data, photographic records, and on-the-ground observations confirm that ice sheets and glaciers are melting.
  • Tide gauges and satellite data show that sea levels are rising.
  • Ground surveys by researchers and citizen scientists, and satellite data, have documented dramatic changes in the geographic ranges and lifecycle timing of Earth’s plants and animals.

As with the temperature record, these datasets have been assembled and analyzed by independent researchers from a variety of specialties. Together, these independent lines of evidence consistently show a rapidly warming world.

What the stolen emails really said

Despite this overwhelming body of evidence, the climate change deniers claim to have proof that global warming is a fraud. Their claim is based on two cherry-picked phrases from the stolen emails, taken wildly out of context. Here they are, with the real story.

In the first email, from 1999, Dr. Phil Jones says “I’ve just completed Mike’s Nature trickof adding in the real temps to each series … to hide the decline.” Denialists are latching desperately to “trick” and “hide the decline” in an attempt to nullify the whole body of evidence for global warming. Here’s what they’ve completely misunderstood:

First, as Nature explains, “’trick’ [is] slang for a clever (and legitimate) technique”. In fact, the technique mentioned in the email was published in Nature by Dr. Michael Mann (thus “Mike’s Nature trick”).

Second, what about the “decline”? This refers to the well-known “divergence problem” between tree ring data and actual temperature records. Prior to about 1960, tree ring density tracked temperature change quite well, so scientists considered tree rings a decent proxy for temperature when or where actual measurements were not available. But for reasons scientists are still trying to figure out, tree rings became less responsive to temperature around 1960. In fact, if you compare actual temperatures to tree rings over that time period, the tree ring record appears to decline, even though we know from thermometers that temperatures continued to increase. So it’s wrong to use the tree rings as part of a temperature reconstruction if you know they’re inaccurate. Dr. Jones was “adding in real [temperature data]” to replace those faulty proxies. Nefarious, eh?

The second email that climate change deniers cling to is by Dr. Kevin Trenberth, in which he said, “The fact is that we can’t account for the lack of warming at the moment and it is a travesty that we can’t.” Here, Trenberth was lamenting the fact that we don’t have adequate observing systems in place to track the details of how heat is distributed among Earth’s systems over short time periods. In fact, Trenberth has explained this problem at length, for example in this paper [PDF]. Remember that science advances by focusing on what we don’t know. In this case, Trenberth was drawing attention to a gap in our understanding of (and the shortage of available data on) short-term internal climate variation. Don’t mistake a discussion of specific uncertainties for a lack of overall understanding.

There’s also been some discussion of emails that reveal scientists’ frustration about what they felt was harassment by the denier camp. Some of these emails are unseemly or even downright insulting to particular individuals, but ultimately we think these comments are merely a reminder that scientists are human and can say not-so-nice things about other people in private.

The bottom line is that there is absolutely no evidence that these scientists altered data. And even if you completely ignore CRU’s temperature reconstructions, you’re still left with an overwhelming amount of independent evidence that Earth is warming rapidly, and that this trend is due to human activities.

The real scandal is that by intentionally sowing confusion, climate change deniers have delayed action on climate change for a very long time. We owe it to our economy, national security, health, and ecosystems—and to future generations—to ignore these kinds of “nontroversies” and finally pass strong cap-and-trade legislation.

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New Climate Report: Life in a Very Different United States

Days Over 100 Degrees (NOAA)NOAA just released a terrific scientific report that explains, in plain English, the current and projected effects of climate change on the U.S. The nonpartisan report, prepared by the 13-agency U.S. Global Change Research Program, tells a grim but important story, clearly and with lots of powerful maps and charts. I encourage you to check it out to see how climate change will affect your area of the country.

Here are some of the “business-as-usual” projections that my colleagues and I find most striking and disturbing:

You think August is hot now?

By the end of this century, we could be in for much more severe summers all across the country.

  • If you live in New Hampshire, summer could feel like it does today in North Carolina (p.107).
  • If you live in Michigan, brace yourself for summers that feel like today’s summers in Oklahoma (p 117).
  • And if you live in Texas, you now experience 10 to 20 days a year over 100 °F. By the last two decades of this century, look for 100 such days – that’s more than three months (p. 90).
  • In 1995, Chicago suffered a heat wave that killed more than 700 people. Chicagoans could experience that kind of relentless heat up to three times a year (p. 117).
  • The Southwest, including cities like Los Angeles and Phoenix, will face worse and more frequent droughts, as spring rains decline by as much as half, snowpacks shrink and melt earlier, and water evaporates more rapidly (p. 129-130).

People who live on the coasts could be a lot closer to the shore

Sea level is projected to rise up to 3 to 4 feet. Here’s what that means for various parts of the country:

  • Portions of New York City and Boston could be regularly flooded by storms and even high tides (p. 150).
  • On the Gulf Coast, approximately 2,400 miles of roads and 250 miles of freight rails are likely to be permanently flooded (p. 62). This area is home to seven of the nation’s ten largest ports and much of our oil and gas industry.
  • Some coastal freshwater sources will be contaminated with saltwater, meaning we can no longer use them for drinking water without expensive desalinization (p. 47)

Your grandchildren will miss out on local icons and specialties

The foods and activities that define different parts of the country are changing.

  • Some western ski resorts could face a 90 percent decrease in snowpack, making the country’s most iconic ski locations just shades of what they are today (p. 133).
  • Thanksgiving might no longer include cranberries produced in the Northeast’s cranberry bogs (p. 73).
  • In the Northwest, salmon will be driven out of about one-third of their habitat. We could start to see the changes in the next ten years (p. 137).

This very thorough scientific report paints a bleak picture of what life will be like in this country if we let pollution continue at today’s rate. The report’s good news is that if we act now, we can avoid the most severe consequences. But the more sobering news is that even if we cut emissions aggressively, not everything in this report can be avoided. This is a first step toward understanding how to prepare for the coming changes.

The American Clean Energy and Security Act, which would take us off the “business-as-usual” path, will come in front of the U.S. House for a vote in a matter of days. This report gives our leaders yet another reason to do the right thing for our country’s future.

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Geo-Engineering: Methadone for Carbon Addiction

Lisa Moore's profileWhat if, instead of reducing the greenhouse gas concentrations that hold excess heat in our atmosphere, we injected something in the atmosphere to reflect sunlight back into space? That’s the idea behind sulfate geo-engineering. As Bill wrote in his post "Can we engineer our way out?", there are a plethora of problems with geo-engineering, but scientists still study it as an option of last resort.

The idea of injecting sulfates into the atmosphere is based on the observation that large volcanic eruptions can cause short-term global cooling. But in addition to the usual problems with geo-engineering (for example, it does nothing to stop ocean acidification from excess CO2), scientists have found a new one. Sulfate geo-engineering could endanger food and water supplies for billions of people in Africa and Asia, according to a recent paper in the Journal of Geophysical Research [PDF].

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Old-Growth Forests Still Taking Up Carbon

Lisa Moore's profileOld Growth ForestOld-growth forests hold vast amounts of carbon from centuries of growth, and this carbon would be released into the atmosphere if the trees were cut down. That much has been known for a long time, which is why Environmental Defense Fund so strongly advocates a plan to reduce deforestation in developing countries.

But new research shows that old-growth forests are even more important than previously thought. According to a new study in Nature, old-growth forests aren’t just standing there maintaining the status quo. They still actively take up CO2 from the atmosphere.

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Posted in International, Plants & Animals / Comments are closed

Climate Change Insights from Mohonk Weather Station

Lisa Moore's profileThere was an interesting story in Tuesday’s New York Times about a unique weather station in upstate New York next to the Mohonk House resort. Most cooperative observer stations move over time, or the area around them is built up, or the observers and observing methods change. Not so at Mohonk.

At Mohonk, the weather observations are done as they were 112 years ago, and only a handful of people have recorded the over 41,000 readings. Plus Mohonk has an extensive database of wildlife sightings, a 77-year record of Mohonk Lake water quality, and an 83-year record of local phenology (the timing of events such as frost, blooms and migrations) – all observed by the same handful of people. This makes the site’s data uniquely valuable:

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Bad Science in Public School Classrooms

Lisa MooreThis post is by Lisa Moore, Ph.D., a scientist in the Climate and Air program at Environmental Defense Fund.

Just when we’re finally having the kind of national conversation we need about global warming, those who are ignoring scientific evidence are making a last-gasp effort to divert our attention: They’re sneaking myths and deceptions into America’s science classrooms.

In Louisiana’s recent “Science Education Act”, they joined forces with advocates of teaching creationism under the guise of promoting “critical thinking” on select scientific topics, including climate change. Signed into law by Governor Bobby Jindal, the law actually provides cover for teachers who want to promote perspectives not founded in science.

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