2070

2070 Global Warming Climate Change  Forecasts

Heat Waves - 2070

2070 to 2099.  Annual number of heat wave days in Los Angeles projected to increase from 12 days to 44 – 95 days for the period 2070 – 2099.  “Analyses of U.S. climate change scenarios through General Circulation Models (GCMs) project that . . . the number of annual heatwave days in Los Angeles, for the 2070 to 2099 time period, will increase from 12 to 44–95." (George Luber, MA, PhD, Michael McGeehin, PhD, MSPH, “Climate Change and Extreme Heat Events,” American Journal of Preventive Medicine, 2008;35(5):429–435, November 2008, p. 431)

Greenhouse Gas Emissions - 2070

2070.  Year scientists believe Earth must be a carbon-neutral planet. “Most of us think that by the year 2070 we need to have a carbon-neutral planet. We can no longer increase the CO2 content of the atmosphere.” (Wallace Broecker interviewed by Kenneth R. Fletcher, “How to stop global warming? CO2 ‘scrubbers,’ a new book says,” Smithsonian Magazine, June 2008)

Ice Free Arctic | Arctic Melting  

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It's always dangerous to make predictions, but we are right on schedule’ for [the disappearance in 2070 of summer Arctic sea ice] to occur.” (1)

 — Mark Serreze, Senior research scientist
National Snow and Ice Data Center
Boulder, Colorado, March 2006 

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2070.  Arctic projected to be entirely ice-free by 2070.  “Current computer models suggest that the Arctic will be entirely ice-free during summer by the year 2070 but some scientists now believe that even this dire prediction may be over-optimistic, said Professor Peter Wadhams, an Arctic ice specialist at Cambridge University.  ‘When the ice becomes so thin it breaks up mechanically rather than thermodynamically. So these predictions may well be on the over-optimistic side,’ he said.  As the sea ice melts, and more of the sun's energy is absorbed by the exposed ocean, a positive feedback is created leading to the loss of yet more ice, Professor Wadhams said.  

‘If anything we may be underestimating the dangers. The computer models may not take into account collaborative positive feedback,’ he said.  Sea ice keeps a cap on frigid water, keeping it cold and protecting it from heating up. Losing the sea ice of the Arctic is likely to have major repercussions for the climate, he said. "There could be dramatic changes to the climate of the northern region due to the creation of a vast expanse of open water where there was once effectively land," Professor Wadhams said. ‘You're essentially changing land into ocean and the creation of a huge area of open ocean where there was once land will have a very big impact on other climate parameters,’ he said.” (Steve Connor, Science Editor, “Global warming 'past the point of no return',” The Independent, Friday, 16 September 2005)

See more recent forecasts of Arctic climate change and an ice free Arctic ocean.

2070.  Arctic sea ice could completely disappear during the summer as early as 2070.  “U.S. scientists said Monday [October 4, 2004] that the extent of Arctic sea ice, the floating mass of ice that covers the Arctic Ocean, is continuing its rapid decline.  Researchers at the [University of Colorado at Boulder's - CU Boulder - National Snow and Ice Data Center] said latest satellite information indicates the September 2004 sea ice extent was 13.4 percent below average, a reduction in area nearly twice the size of Texas.  In 2002, the decline in arctic sea ice during September -- which traditionally marks the end of the summer melt season -- was about 15 percent, a record low.  Sea-ice decline during September has averaged about 8 percent over the past decade, researchers said, and current computer models suggest the sea ice could completely disappear during the summer as early as 2070.” (“Summer Arctic Sea Ice In Decline,” United Press International, Monday, October 4, 2004 citing reported by the National Snow and Ice Data Center, “Arctic Sea Ice Declines,” October 4, 2004.  See also Arctic Sea Ice News & Analysis)

Climate Change Flooding

2070.  Number of people exposed to coastal flooding could more than triple by 2070 from 40 million to 150 million worldwide.  “The impact of climate change and urban development could more than triple the number of people around the world exposed to coastal flooding by 2070, with Kolkata being the most vulnerable city followed by Mumbai, a new report [Ranking of the World's Cities Most Exposed to Coastal Flooding Today and in the Future] said.  The report, prepared by the Organisation for Economic Cooperation and Development (OECD), said by 2070, Kolkata will be the most vulnerable with the exposed population expected to increase over seven times to more than 14 million people. 

Over the coming decades, the unprecedented growth and development of the Asian mega-cities will be a key factor in driving the increase in coastal flood risk globally, it said adding, in terms of population exposure, Kolkata is closely followed by Mumbai, Dhaka, Guangzhou, Ho Chi Minh City, Shanghai, Bangkok and Yangon (Myanmar).  Miami is in ninth place and would be the only top ten city in a currently developed country, while Hai Phong in Vietnam is ranked tenth. 

Around half of the total population exposure to coastal flooding caused by storm surge and damage from high winds is contained in just ten cities today.

Mumbai has the highest number of people exposed to coastal flooding.  Ranking port cities with high exposure and vulnerability to climate extremes, it found that around 150 million people could be exposed to a one-in-100 year coastal flood event by 2070, up from 40 million today. The estimated financial impact of such an event would also rise USD 35 trillion by 2070, up from USD 3 trillion today.” (Dharam Shourie, “By 2070, Kolkata,Mumbai to be most vulnerable to coastal flood,”  PTI - The Press Trust of India Ltd., New York, December 5, 2007) 

Snowpack Levels and Global Warming

 2070.  Complete disappearance of snowpacks in the northern Rocky Mountains by 2070.  “Fyfe and Flato (1999) modeled the effects of climate change on snowpacks in the northern Rocky Mountains during the 21st century. Their simulations showed shrinking snowpacks during the first two-thirds of the century with complete disappearance by 2070. They based their simulations in part on the Canadian Coupled Global Circulation Model which projects higher temperature increases than the British Hadley Circulation Model (Table 3.8).”  Snow pack, snow cover.  (Frederic H. Wagner et al, Preparing for a Changing Climate - The Potential Consequences of Climate Variability and Change, Rocky Mountain/Great Basin Regional Climate Change Assessment, A Report of the Rocky Mountain/Great Basin Regional Assessment Team for the U.S. Global Change Research Program, U.S. Geological Survey, Utah State University, 2003, p. 139)