Share

Study: 97% Agreement on Manmade Global Warming

Angela Fritz
Published: May 16, 2013

The scientific agreement that climate change is happening, and that it's caused by human activity, is significant and growing, according to a new study published Thursday

The research, which is the most comprehensive analysis of climate research to date, finds that 97.1% of the studies published between 1991 to 2011 that expressed a position on manmade climate change agreed that it was happening, and that it was due to human activity.

The study looked at peer reviewed research that mentioned climate change or global warming.  Peer review is the way that scientific journals approve research papers that are submitted. In peer review, group of scientists that weren't involved in the study, but who are experts in the field, look at the research being submitted and have approved that it meets scientific process standards, and the standards of that journal.

In 2011, 521 of those peer reviewed papers agreed that climate change is real, and that human activity is the cause.  Nine papers in 2011 disagreed.

John Cook, founder of skepticalscience.com and the lead author on the study, said the motivation for the analysis was the importance of scientific consensus in shaping public opinion, and therefore policy. "When people understand that climate scientists agree on human-caused global warming, they're more likely to support climate policy," Cook said. "But when the public are asked how many climate scientists agree that humans are causing global warming, the average answer is around 50%."

This "consensus gap" is what Cook and the research team is trying to close. "Raising awareness of the scientific consensus is a key step towards meaningful climate action," Cook said.

This study is not the first to examine the overwhelming agreement among climate scientists. Surveys of actively publishing climate scientists as well as analyses of climate change papers have shown similar results.

In 2004 Naomi Oreskes, Professor of History and Science Studies at the University of California San Diego, published what many scientists consider the seminal study on climate change consensus. She also co-authored the book Merchants of Doubt, which identifies and examines the similarities between today's climate change conversation and previous controversies over tobacco smoking, acid rain, and the hole in the ozone layer.

(MORE: America's First Climate Refugees)

Oreskes believes that the public isn't aware of the consensus because of deliberate efforts to cause confusion. "There has been a systematic attempt to create the impression that scientists did not have a consensus, as part of a broader strategy to prevent federal government action," Oreskes said. "The public have been confused because people have been trying to confuse us."

The study published Thursday is the first to take so many papers and authors into account. Doing a search on the popular science article website Web of Science for "climate change" or "global warming" produces over 12,000 results. Of these, 4,014 papers were identified to state a position on climate change. Among those, 3,896, or 97.1% endorsed the consensus that climate change was happening and that it was caused by human activity.

In an interesting result, Cook and his team found that over time, scientists tend to express a position on climate change less and less in their research papers. This is likely a result of consensus -- that if a scientific conclusion has been reached, there's no need to continue to state that conclusion in new research. "Scientists tend to take the consensus for granted," says Cook, "perhaps not realizing that the public still think it's a 50:50 debate."

MORE: 10 Places to See Before They Disappear

Galapagos Islands

Galapagos Islands

A boat sails past Bartolome Island on the Galapagos archipelago. The Galapagos Islands, off the coast of Ecuador in the Pacific, are threatened by tourism. From 1978-2010, the islands were on the U.N.'s list of World Heritage Sites, precious places at risk from environmental threats or overuse. (Martin Bernetti/AFP/Getty Images)

  • Galapagos Islands
  • The Maldives
  • The Great Barrier Reef
  • Venice
  • The Dead Sea
  • The Alps
  • Madagascar
  • The Congo Basin
  • Glacier National Park
  • Taj Mahal

Featured Blogs

2014 Holiday Shopping Guide for the Weather and Climate Change Enthusiast

By Dr. Jeff Masters
November 28, 2014

Every serious weather enthusiast deserves a Personal Weather Station (PWS)! Recommended for this year: The Netatmo Weather Monitor ($179, or enter the promo code WUNDERGROUND to get the station for $149), which monitors your living environment and wirelessly transmits all your data to your Smartphone.

October 2014 Global Weather Extremes Summary

By Christopher C. Burt
November 22, 2014

October was globally the warmest such on record according to NOAA (see Jeff Master’s blog for more about this). Extreme heat waves affected southern South America and California with exceptional warmth in Europe and Australia as well. Intense rainfalls plagued southern France and Italy. Deadly flooding and mudslides occurred in Sri Lanka. A blizzard in Nepal killed at least 43 trekkers and their guides. Hurricane Gonzalo was the first CAT 4 tropical storm in three years to form in the Atlantic Basin and struck Bermuda. Typhoon Vongfong was the Earth’s most powerful storm of the year.

Live Blog: Tracking Hurricane Arthur as it Approaches North Carolina Coast

By Shaun Tanner
July 3, 2014

This is a live blog set up to provide the latest coverage on Hurricane Arthur as it threatens the North Carolina Coast. Check back often to see what the latest is with Arthur. The most recent updates are at the top.

Tropical Terminology

By Stu Ostro
June 30, 2014

Here is some basic, fundamental terminology related to tropical cyclones. Rather than a comprehensive and/or technical glossary, this represents the essence of the meaning & importance of some key, frequently used terms.

2013-14 - An Interesting Winter From A to Z

By Tom Niziol
May 15, 2014

It was a very interesting winter across a good part of the nation from the Rockies through the Plains to the Northeast. Let's break down the most significant winter storms on a month by month basis.

What the 5th IPCC Assessment Doesn't Include

By Angela Fritz
September 27, 2013

Melting permafrost has the potential to release an additional 1.5 trillion tons of carbon into the atmosphere, and could increase our global average temperature by 1.5°F in addition to our day-to-day human emissions. However, this effect is not included in the IPCC report issued Friday morning, which means the estimates of how Earth's climate will change are likely on the conservative side.