. Earth Science News .




.
CLIMATE SCIENCE
The human cause of climate change: Where does the burden of proof lie?
by Staff Writers
London, UK (SPX) Nov 08, 2011

File image.

The debate may largely be drawn along political lines, but the human role in climate change remains one of the most controversial questions in 21st century science. Writing in WIREs Climate Change Dr Kevin Trenberth, from the National Center for Atmospheric Research, argues that the evidence for anthropogenic climate change is now so clear that the burden of proof should lie with research which seeks to disprove the human role.

In response to Trenberth's argument a second review, by Dr Judith Curry, focuses on the concept of a 'null hypothesis' the default position which is taken when research is carried out. Currently the null hypothesis for climate change attribution research is that humans have no influence.

"Humans are changing our climate. There is no doubt whatsoever," said Trenberth. "Questions remain as to the extent of our collective contribution, but it is clear that the effects are not small and have emerged from the noise of natural variability. So why does the science community continue to do attribution studies and assume that humans have no influence as a null hypothesis?"

To show precedent for his position Trenberth cites the 2007 report by the Intergovernmental Panel on Climate Change which states that global warming is "unequivocal", and is "very likely" due to human activities.

Trenberth also focused on climate attribution studies which claim the lack of a human component, and suggested that the assumptions distort results in the direction of finding no human influence, resulting in misleading statements about the causes of climate change that can serve to grossly underestimate the role of humans in climate events.

"Scientists must challenge misconceptions in the difference between weather and climate while attribution studies must include a human component," concluded Trenberth. "The question should no longer be is there a human component, but what is it?"

In a second paper Dr Judith Curry, from the Georgia Institute of Technology, questions this position, but argues that the discussion on the null hypothesis serves to highlight fuzziness surrounding the many hypotheses related to dangerous climate change.

"Regarding attribution studies, rather than trying to reject either hypothesis regardless of which is the null, there should be a debate over the significance of anthropogenic warming relative to forced and unforced natural climate variability," said Curry.

Curry also suggested that the desire to reverse the null hypothesis may have the goal of seeking to marginalise the climate sceptic movement, a vocal group who have challenged the scientific orthodoxy on climate change.

"The proponents of reversing the null hypothesis should be careful of what they wish for," concluded Curry. "One consequence may be that the scientific focus, and therefore funding, would also reverse to attempting to disprove dangerous anthropogenic climate change, which has been a position of many sceptics."

"I doubt Trenberth's suggestion will find much support in the scientific community," said Professor Myles Allen from Oxford University, "but Curry's counter proposal to abandon hypothesis tests is worse. We still have plenty of interesting hypotheses to test: did human influence on climate increase the risk of this event at all? Did it increase it by more than a factor of two?"

All three papers are free online: Trenberth. K, "Attribution of climate variations and trends to human influences and natural variability"; Curry. J, "Nullifying the climate null hypothesis"; Allen. M, "In defense of the traditional null hypothesis: remarks on the Trenberth and Curry opinion articles"

Related Links
Wiley-Blackwell
Climate Science News - Modeling, Mitigation Adaptation




.
.
Get Our Free Newsletters Via Email
...
Buy Advertising Editorial Enquiries




.

. Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle



CLIMATE SCIENCE
Biggest spike ever in global warming gases: US
Washington (AFP) Nov 4, 2011
Harmful carbon emissions from burning fossil fuels made their biggest ever annual jump in 2010, according to the US Department of Energy's latest world data released this week. China led the way with a spike of 212 million metric tons of carbon in 2010 over 2009, compared to 59 million metric tons more from the United States and 48 million metric tons more from India in the same period. ... read more


CLIMATE SCIENCE
Thai opposition challenges PM over flood budget

Tokyo city starts radiation tests on food in shops

Social media use soars in flood-hit Thailand

Current Training Programs May Not Prepare Firefighters to Combat Stress

CLIMATE SCIENCE
Electronics set to power US holiday sales: report

An Incredible Shrinking Material

Tying atomic threads in knots may produce material benefits

GMV Awarded Contract For Paz Satellite Control Center

CLIMATE SCIENCE
Geologists find ponds not the cause of arsenic poisoning in India's groundwater

Sea life "must swim faster to survive"

Crop diversity myths persist in media

NOAA designates critical habitat for black abalone

CLIMATE SCIENCE
NASA Airborne Mission Maps Remote, Deteriorating Glaciers

Peatland carbon storage is stabilized against catastrophic release of carbon

New webcam allows world to watch live polar bear migration

Campaigners push for vast Antarctic marine reserve

CLIMATE SCIENCE
China food chain shares up after buyout gets OK

Nitrogen Fertilizers' Impact on Lawn Soils

Research team unravels tomato pathogen's tricks of the trade

Peru's Congress approves 10-year GMO ban

CLIMATE SCIENCE
Thai PM to skip APEC summit due to flood crisis

Orange smoke billows out of Congolese volcano

Aid groups warn over Pakistan flood fund

More than 500 die in Thai floods

CLIMATE SCIENCE
Climate to widen sleeping sickness risk to southern Africa

Hitting the bottle to solve Nigeria's housing problem

China denies abuses in Zambian mines

Kenya claims Somali rebels receive third weapons airdrop

CLIMATE SCIENCE
The benefits of being the first to settle

Human skin begins tanning in seconds, and here's how

Jawbone found in England is from the earliest known modern human in northwestern Europe

Increased use of bikes for commuting offers economic, health benefits


.

The content herein, unless otherwise known to be public domain, are Copyright 1995-2011 - Space Media Network. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement