Study: It Is "Very Likely" That Scientists Are Confusing Us About Global Warming

Alex E. Proimos/Wikimedia Commons

by Chris Mooney, Mother Jones:  http://www.motherjones.com/environment/2014/04/ipcc-global-warming-doubt-psychology
 
The United Nations' Intergovernmental Panel on Climate Change is a big, big production.

Its reports, released roughly every five years, are considered the gold standard of climate science, and are always a major media event.

Thousands of scientists contribute to the reports, all of them volunteering their expertise to make the world just a little bit better.

There's just one problem: According to a new paper out in Nature: Climate Change, the IPCC may be dramatically undermining its own work through one of its trademark tools: a system of language that the group uses to describe how certain (or uncertain) researchers are about its scientific findings.

According to the new study, this system (which involves describing conclusions as "likely," "very likely," and so on) has the unfortunate effect of making people less sure than they ought to be of the IPCC's most important conclusions.

Unintentionally, then, the IPCC seems to be doing just what climate skeptics and deniers are so often accused of: sowing doubt.

The new study, by psychologist David Budescu of Fordham University and his colleagues, is actually the latest in a string of papers by these researchers showing that people systematically misunderstand what the IPCC means when it uses phrases such as "likely" and "very likely" to describe the strength of its conclusions.

Take, for instance, the IPCC's famous finding, in 2007, that "most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic [human-produced] greenhouse gas concentrations."

According to Budescu's research, while the IPCC intends for "very likely" to mean a greater than 90 percent likelihood, that's not necessarily the message the average person hears. Instead, when Budesco and his colleagues asked members of the public to assign a probability to the term "very likely," the mean estimate people gave was just 62 percent.

In general, Budescu finds that when the IPCC assigns a high level of certainty to a conclusion, using terms like "very likely" or "extremely likely," people adjust their interpretation downward, taking the conclusion to be considerably less certain than it actually is.

When the IPCC assigns a low probability, meanwhile, people adjust their assessment upwards, taking the conclusion to be considerably more certain than it actually is.

Thus for instance, when the IPCC calls a conclusion "very unlikely," it means there is less than a 10 percent chance that it's true. But the mean estimate given by members of the public for what this term means is 41 percent.

To see how much confusion this can cause, just consider another 2007 IPCC statement: "It is very unlikely that climate changes of at least the seven centuries prior to 1950 were due to variability generated within the climate system alone."

Budescu and his colleagues have found these results consistently, across samples. In 2009, they found as much with a sample of college students and members of a single university community. In 2012, they did so again with a nationally representative sample of Americans. And in the new Nature: Climate Change study, they present the same finding with citizens of 25 countries, having now conducted the research in multiple languages.

Again and again, it would seem that the IPCC's language about uncertainty backfires, and undermines itself. It sows doubt in the minds of the public.

Moreover, given that Budescu's first paper on this subject was published in 2009, the IPCC should presumably know by now that its practices appear to have caused the public to be far more doubtful than it should be about the science of climate change.

In fairness, the current approach exists for a reason: it avoids requiring scientists to be too precise about their level of certainty, and it allows for the possibility that different scientists would come up with somewhat different numbers for their extent of certainty.

"I think that they are finding their way slowly, and they are trying things," remarks Budescu of the IPCC's uncertainty practices. "A lot of the things that they are trying make sense, and are reasonable. I think they are slow in adjusting."

Minerva Studio/Shutterstock

Solving this problem would be quite simple: Budescu's research shows that people's misunderstanding of the IPCC's language about uncertainty decreases if you simply include a numeric value next to the standard uncertainty language.

Thus, instead of merely saying "very likely," the IPCC could just prominently add "(> 90% likelihood)," or something similar.

As it is, these numerical values are included as a footnote in the IPCC's widely read "Summary for Policymakers" reports, and a box in the much less widely read technical report; Budescu's research suggests they should appear throughout the text.

It is critical to underscore just how problematic the IPCC's ill-calibrated uncertainty language is. The IPCC produces many thousands of words in its reports, and spends five or more years doing so; and yet generally, there is one sentence from each report that is almost universally quoted in the press, on blogs, and beyond.

It is always the sentence that describes how certain the IPCC is about the conclusion that humans are causing global warming; and that sentence always contains the IPCC's confusing uncertainty-speak.

In 2001, the IPCC found the conclusion "likely"; in 2007, "very likely"; and in 2013, "extremely likely." To the IPCC, that meant "greater than 66 percent likelihood," "greater than 90 percent," and "greater than 95 percent," respectively. Based on the latest research, the public took away a very different message indeed.

Journalists may partly mitigate this problem, to be sure. Outlets like the New York Times and the Washington Post, in their coverage of last year's IPCC report, took it upon themselves to include a numerical probability value as they explained the IPCC's conclusion that it is now "extremely likely" that humans are driving global warming.

Yet not all media outlets did: take this report from ABC News, for instance; it included a clip of an IPCC official saying it's "extremely likely" that humans are causing climate change but did not include any numerical explanation of what that means.

The IPCC has been extensively faulted in the past for a wide range of communications failures. Not all of them have easy fixes, but this one surely does.
 

Chris Mooney, Correspondent

Chris Mooney is a science and political journalist, podcaster, and the host of Climate Desk Live. He is the author of four books, including the New York Times bestselling The Republican War on Science. RSS | Twitter

Sorry, Joe Hockey – Canberra is Australia's Home of Wind Farms

Not a fan of wind turbines (AAP Image/Alan Porritt)

by Hugh Saddler, Australian National University

We now know that Treasurer Joe Hockey is not a fan of wind farms, on aesthetic grounds at least.

On Friday he told Macquarie Radio’s Alan Jones he finds the view “utterly offensive” and “a blight on the landscape”.

The vista that has so irked Mr Hockey can be seen while driving along the Federal Highway on the western side of Lake George.

Across the water, dotted along the lake’s eastern shore, are turbines belonging to the Capital Wind Farm, the largest of six wind farms now operating to the north and northeast of Canberra.

The bad news for the Treasurer is that the Australian Capital Territory is one of the few places where wind farms are a growth industry, and are set to remain so regardless of what happens to the federal Renewable Energy Target.

Windy city

The area north of Canberra has some of the best wind resources anywhere in Australia.

Since it was commissioned in 2011, the Gunning Wind Farm, about 70 km north of the capital, has consistently achieved a capacity factor (the ratio of power generated, relative to the facility’s theoretical maximum) of 40%, making it one of the best-performing wind farms in the country and, indeed, the world.

Unsurprisingly, there are several more wind farms planned for the area around Canberra - some quite advanced in the planning process.

The total capacity of these projects is more than 1,000 megawatts. For comparison, the total capacity of operating wind farms currently supplying the National Electricity Market is just over 2,300 MW.

Power and certainty

However, like many wind farm projects at a similar stage of development around Australia, most of the projects in the Canberra region, including some which have received planning approval, are yet to sign a power purchase agreement with an electricity retailer or other party. This means that they do not have the financial certainty needed to start construction.

The main purchasers of wind-generated electricity are electricity retailers which, until now, have been legally required to buy a specified (and increasing) quantity of renewable electricity each year up to 2020 under the Renewable Energy Target (RET) scheme.

Most retailers already have contracts in place for all the renewable electricity they need now and for at least the next year. In normal circumstances, retailers would be signing up new supplies of renewable electricity to cover their growing obligations from 2016 onwards.

Circumstances, however, are not normal.

The RET scheme is undergoing its second review in two years, and several ministers - including Mr Hockey - have expressed what can only be described as extreme scepticism about the scheme’s merits. Many backbenchers and influential advisers are openly hostile to it.

ACT embracing wind power

Perhaps Mr Hockey thinks that winding back the RET scheme will ensure that no more wind farms appear to blight the view from his car. But unfortunately for him, the one area where new wind farms may continue to be built, even if the RET is scrapped, is around Canberra.

Earlier this year, the ACT government called for tenders to supply 200 MW of wind generation, as a major step towards its target of sourcing 90% of the territory’s electricity use from renewable sources.

The electricity generated by the contracted wind farms would not be supplied explicitly to the ACT. It will be fed into the National Electricity Market (NEM), where it will displace other sources that would otherwise be required to meet the territory’s power demand.

But the ACT wind contracts will not be registered under the RET scheme because the territory’s government is aiming to make extra reductions in overall emissions, even if the nationwide RET scheme survives in something like its present form.

The tender documents state that the selected wind farm(s) may be located anywhere within the NEM, but also that tenderers will have to deliver economic benefits to the ACT. The territory government clearly expects that successful bidders will have projects close to Canberra.

Powering into the future

The ACT government has said that it will eventually commission about 382 MW of wind and 91 MW of solar generation, which, together with some smaller renewable sources, should be sufficient to achieve the 90% target.

This target is a core element of the territory’s legislated plan to cut greenhouse emissions, including from power stations supplying the ACT with electricity, by 40% relative to 2000 levels by 2020.

This makes the ACT unique among Australia’s state, territory and federal governments. It is the only one with a legislated emissions-reduction target and a credible plan to make it happen.

Unlike the rest of Australia, the ACT has negligible emissions from industry, agriculture, forestry and land use changes - the majority of its emissions come from from electricity generation and transport.

The government has concluded that it will be hard to make major reductions in emissions from transport fuels by 2020, but much easier to cut electricity-generation emissions. So making deep cuts in electricity emissions would be the cheapest way to hit the overall emissions target.

Royalla Solar Farm - just a short drive from Canberra Grahamec/Wikimedia Commons, CC BY

While the current tender is the first for wind generation, the ACT government has already contracted 40 MW of large-scale solar power.

The first contracted project, the 20 MW Royalla Solar Farm, is almost finished and will soon be up and running. It’s about 20 km south of Canberra along the Monaro Highway, and is easy to spot from a car.

Let’s hope, if Mr Hockey drives that way, that he prefers looking at solar panels rather than wind turbines.


Hugh Saddler does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.

This article was originally published on The Conversation. Read the original article.