Navigation Links
Stanford climate scientists forecast permanently hotter summers

The tropics and much of the Northern Hemisphere are likely to experience an irreversible rise in summer temperatures within the next 20 to 60 years if atmospheric greenhouse gas concentrations continue to increase, according to a new climate study by Stanford University scientists. The results will be published later this month in the journal Climatic Change.

In the study, the Stanford team concluded that many tropical regions in Africa, Asia and South America could see "the permanent emergence of unprecedented summer heat" in the next two decades. Middle latitudes of Europe, China and North America including the United States are likely to undergo extreme summer temperature shifts within 60 years, the researchers found.

"According to our projections, large areas of the globe are likely to warm up so quickly that, by the middle of this century, even the coolest summers will be hotter than the hottest summers of the past 50 years," said the study's lead author, Noah Diffenbaugh, an assistant professor of environmental Earth system science and fellow at the Woods Institute for the Environment at Stanford. The study is co-authored by Stanford research assistant Martin Scherer.

"When scientists talk about global warming causing more heat waves, people often ask if that means that the hottest temperatures will become 'the new normal,'" Diffenbaugh said. "That got us thinking at what point can we expect the coolest seasonal temperatures to always be hotter than the historically highest temperatures for that season?"

Climate models, past and future

To determine the seasonal impact of global warming in coming decades, Diffenbaugh and Scherer analyzed more than 50 climate model experiments including computer simulations of the 21st century when global greenhouse gas concentrations are expected to increase, and simulations of the 20th century that accurately "predicted" the Earth's climate during the last 50 years. The analysis revealed that many parts of the planet could experience a permanent spike in seasonal temperatures within 60 years.

"We also analyzed historical data from weather stations around the world to see if the projected emergence of unprecedented heat had already begun," Diffenbaugh said. "It turns out that when we look back in time using temperature records, we find that this extreme heat emergence is occurring now, and that climate models represent the historical patterns remarkably well."

According to both the climate model analysis and the historical weather data, the tropics are heating up the fastest. "We find that the most immediate increase in extreme seasonal heat occurs in the tropics, with up to 70 percent of seasons in the early 21st century (2010-2039) exceeding the late-20th century maximum," the authors wrote.

Tropical regions may see the most dramatic changes first, but wide swaths of North America, China and Mediterranean Europe are also likely to enter into a new heat regime by 2070, according to the study.

Environmental impact

This dramatic shift in seasonal temperatures could have severe consequences for human health, agricultural production and ecosystem productivity, Diffenbaugh said. As an example, he pointed to record heat waves in Europe in 2003 that killed 40,000 people. He also cited studies showing that projected increases in summer temperatures in the Midwestern United States could reduce the harvest of staples, such as corn and soybeans, by more than 30 percent.

Diffenbaugh was surprised to see how quickly the new, potentially destructive heat regimes are likely to emerge, given that the study was based on a relatively moderate forecast of greenhouse gas emissions in the 21st century.

"The fact that we're already seeing these changes in historical weather observations, and that they match climate model simulations so closely, increases our confidence that our projections of permanent escalations in seasonal temperatures within the next few decades are well founded," Diffenbaugh said.


Contact: Mark Shwartz
Stanford University

Related biology news :

1. Circadian clock may be critical for remembering what you learn, Stanford researchers say
2. Stanford researchers: Global warming is killing frogs and salamanders in Yellowstone Park
3. Key link in how plants adapt to climate discovered by Stanford researchers
4. Cell movements totally modular, Stanford study shows
5. Powerful online tool for protein analysis provided pro bono by Stanford geneticist
6. New World post-pandemic reforestation helped start Little Ice Age, say Stanford scientists
7. Stanford launches $100 million initiative to tackle energy issues
8. Biofuels boom could fuel rainforest destruction, Stanford researcher warns
9. From stem cells to new organs: Stanford and NYU scientists cross threshold in regenerative medicine
10. Stanford researchers develop biodegradable substitutes for wood, plastic bottles and other materials
11. Stanford scientists find new solutions for the arsenic-poisoning crisis in Asia
Post Your Comments:
(Date:10/29/2015)... Oct. 29, 2015  Rubicon Genomics, Inc., today ... distribution of its DNA library preparation products, including ... new ThruPLEX Plasma-seq kit. ThruPLEX Plasma-seq has been ... of NGS libraries for liquid biopsies--the analysis of ... prognostic applications in cancer and other conditions. Eurofins ...
(Date:10/27/2015)... , October 27, 2015 ... Semantic Gaze Mapping technology (ASGM) automatically maps data from ... Tracking Glasses , so that they can be ... --> Munich, Germany , October 28-29, ... maps data from mobile eye tracking videos created with ...
(Date:10/23/2015)... Oct. 23, 2015 Research and Markets ( ... "Global Voice Recognition Biometrics Market 2015-2019" report to ... --> The global voice recognition biometrics market to ... --> --> The ... prepared based on an in-depth market analysis with inputs ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... , Nov. 24, 2015 /CNW/ - iCo Therapeutics ("iCo" ... reported financial results for the quarter ended September ... in Canadian dollars and presented under International Financial ... States ," said Andrew Rae , ... regarding iCo-008 are not only value enriching for ...
(Date:11/24/2015)... , ... November 24, 2015 , ... ... of the year and one of the premier annual events for pharmaceutical manufacturing: ... from 8–11 November 2015, where ISPE hosted the largest number of attendees in ...
(Date:11/24/2015)... Global, Inc., a worldwide provider of clinical research services headquartered in ... company has set a new quarterly earnings record in Q3 of ... for Q3 of 2014 to Q3 of 2015.   ... with the establishment of an Asia-Pacific office ... Kingdom and Mexico , with the ...
(Date:11/24/2015)... ... November 24, 2015 , ... This fall, global software solutions ... in five states to develop and pitch their BIG ideas to improve health and ... are competing for votes to win the title of SAP's Teen Innovator, an all-expenses ...
Breaking Biology Technology: