skip to main content

→ Top Stories:
Clean Power plan
Safe Chemicals

Dan Lashof’s Blog

This is What Global Warming Looks Like

Dan Lashof

Posted September 16, 2010

, , , , , , , ,
Share | | |

UPDATED: New ad-free video link. New NASA data for January-August 2010.

Summer 2010 was the worst summer ever for many Americans and even more Russians, Pakistanis, and Chinese. Today NRDC released a report analyzing U.S. temperatures and a video highlighting weather extremes in the United States, Russia, Pakistan, and China in summer 2010.

The report analyzes summer 2010 (June, July and August) data from 1,218 weather stations in NOAA’s Historic Climatology Network (HCN). The report reveals that 153 locations recorded their hottest summer on record and nearly one in three stations recorded average temperatures among their five hottest on record.

Even more telling: average nighttime low temperatures were the hottest ever recorded at nearly one in four of the HCN weather stations. This means that at 278 stations the average nighttime low temperatures for June, July and August 2010 were hotter than at any time since 1895. More than half the stations recorded average nighttime low temperatures among their five hottest on record.

Nighttime temperatures are more sensitive to the buildup of heat-trapping pollution in the atmosphere than daytime temperatures because increases in atmospheric aerosols and cloud cover have counteracted some of the warming effect of greenhouse gases during the day. Hot, stagnant nights can prove even more harmful than daytime highs as vulnerable populations (particularly the very young and the elderly) are unable to cool down and get relief from the stress of the daytime heat.

In addition to the national overview, for the 37 states that contain weather stations where summer 2010 records were set we have developed state maps showing the name and location of each weather station that set a record and accompanying tables that show for each weather station how summer 2010 compared to all other summers on record. We also have a Google Earth data layer that allows you to zoom in on any part of the country.

Some highlights of the state-by-state analysis:

  • In Maryland, 15 of the 16 stations in the Historical Climatology Network reported their hottest average summer on record, and 12 reported their hottest average nighttime low temperatures on record. All 16 Maryland stations reported average temperatures and average nighttime low temperatures among their five hottest on record in summer 2010.
  • In Florida, 9 out of 22 stations reported their hottest average temperatures on record in summer 2010 and 8 reported their hottest average nighttime low temperatures on record. In Fort Lauderdale the average nighttime low temperature for the full summer was 77.7 degrees. Nearly all—21 of 22—Florida stations reported average nighttime low temperatures among their five hottest on record in summer 2010.
  • The Midwest also experienced very warm nighttime temperatures. In Illinois and Indiana, 92% and 86% of the stations, respectively, reported average nighttime low temperatures among their five hottest on record.
  • Considering all 513 weather stations east of the Mississippi, 40 percent reported their hottest average nighttime low temperatures in 2010 and over 80 percent reported average nighttime low temperatures among their five hottest on record.

NOAA has released its own analysis of summer 2010, which Heidi Cullen discusses on Climate Central. Among its findings:

This last point is worth emphasizing. Not only was it hot, but it was particularly hot where most of the U.S. population lives. And it was not just hot during the day, but it didn’t cool off at night. The net effect was that more people had to run air conditioners for more hours than ever before to stay healthy, while people without access to air conditioning faced the most serious health risks.

The record heat this summer was not isolated to the United States. Global temperature data compiled by NASA show that the first eight months of 2010 comprise the hottest such period on record and a preliminary report from NOAA released yesterday indicates that January through August was tied for the hottest on record. This comes on top of the warmest decade on record (2000-2009), which surpassed the previous record set by the 1990s, which itself supplanted the 1980s as the warmest decade on record at that time.

Record-high temperatures are not the only weather extremes we have seen in 2010. Because the atmosphere can hold more moisture as it warms, there is more rapid evaporation when it is dry and more intense rainfall when it is wet. The result is an increase in severe droughts and floods. As we have seen in Russia, Pakistan, China, and the United States, the results have been tragic. Russia has seen hundreds of wildfires and thousands of deaths in Moscow during its worst heat wave on record. In Pakistan more than a thousand people have been killed, and a million more displaced by floods. Flooding this year has also killed more than a thousand people in China, and more than 50 in Iowa and Tennessee.

But pictures really are worth a thousand words, which is why we produced this video:


While one hot summer does not prove that global warming is happening, the long-term global trend does, according to the U.S. National Academy of Sciences, among others. Similarly, we can’t attribute any specific extreme event to global warming with confidence, but we know that we are loading the dice. More record heat and more extreme droughts and floods can be expected in the future as heat-trapping pollution continues to build up in our atmosphere.

Share | | |


StyloSep 16 2010 09:01 PM

" was particularly hot where most of the U.S. population lives. And it was not just hot during the day, but it didn’t cool off at night."

This sounds exactly like the urban heat island effect. It can account for most of this 0.8C warming in GHCN's temp record -- a record that only goes for 120 years. They've been specially selecting sites near population centres to help tweak up the temperatures. In any case 0.8C is nothing.

There really is no climate crisis except in the minds of scaremongers and scaredy-cats. In Australia the temperatures are moderate and we have rain. The southern hemisphere has been having record cold. I notice you conveniently ignored that.

Mark BtokSep 16 2010 11:23 PM

Before The People Awaken!
With the global elite in a race against time to enforce their draconian eco-fascist agenda before more of the public realize that the entire climate change con is a rigged game, alarmists are getting increasingly desperate and transparently thuggish in their rhetoric.
The mask of the man-made global warming movement is slowly being ripped away to reveal the true nature of what we face – a gang of hardcore control freaks who have hijacked well-placed environmental concerns as a vehicle through which to enact their religion of death – eugenics.
This was exemplified earlier this week when Bill Gates was caught in a controversy after he advocated the use of death panels to make rulings on denying health care to the elderly. Gates’ justification that killing old people could save money to preserve jobs was a classic case of social cannibalism, the end justifies the means, and it revealed the true nature of the eco-fascist agenda.
The Bill and Melinda Gates Foundation funds vaccines for the third world to the tune of billions, and yet in his own speeches Gates has advocated using vaccines to lower global population, all in the name of reducing CO2 emissions and combating global warming. In other words, Gates invokes the vaccines he funds in the name of improving health care as a tool of forced sterilization.
Gates’ call for death panels was mimicked by a September 2009 Newsweek article entitled “The Case For Killing Granny,” in which writer Evan Thomas made the case for rationing health care by denying old people treatment.
The eugenicist health care argument shares a central parallel with the environmentalist screed – using the threat of artificial scarcity to uphold the role of the state as an authoritarian re-distributor
This idea is embraced by a growing cult of climate change cult members, who are openly calling for freedom to be crushed and humans to be exterminated in the name of saving the planet.
Top environmentalist and creator of the Gaia hypothesis James Lovelock told the Guardian earlier this year that “democracy must be put on hold” to combat global warming and that “a few people with authority” should be allowed to run the planet.
In a recent book, author and environmentalist Keith Farnish called for acts of sabotage and environmental terrorism in blowing up dams and demolishing cities in order to return the planet to the agrarian age. Prominent NASA global warming alarmist and Al Gore ally Dr. James Hansen endorsed Farnish’s book. Full article at:

Re: End Game Complete Video:
Two Party:

Dan LashofSep 17 2010 08:47 AM

Actually the NOAA HCN dataset was specifically designed to remove any urban heat island effect (follow the link in my post to read NOAA's methodology). And its really hard to explain the increase in ocean heat content by an urban heat island effect. As for the Southern Hemisphere, it is accounted for in the global data I cite. See the graph produced by NASA (again, follow the link in my post), it shows that the Southern Hemisphere has not been as hot as the Northern Hemisphere this year, but it certainly isn't cool enough to compensate for the very hot conditions in the tropics and at high latitudes.
Finally, 0.8C is not the issue in and of itself. It's what comes along with it and what is to come as temperatures rise further. See the video.

larry wagnerSep 17 2010 11:06 AM

Why doesn't the author mention the unusually cold summer in California?

SAN DIEGO -- The average high temperature for July at Lindbergh Field -- San Diego's official reporting station -- was the lowest in nearly 100 years, the National Weather Service reported Sunday.
The average daily maximum was 69.4 degrees, the fifth lowest on record and the coolest since 1916, according to the NWS. --

Michael JonesSep 17 2010 11:26 AM

Perhaps we should continue with our experiment and continue INCREASING our emissions and see what happens.
After all, we can not be too careful about theories and outcomes.
Though there is a sound science to support Human Global Warming, it's still a matter of degree and at what time frame.
Remember haste makes waste, and for the record it's now called "global climate dispurtion"

larrySep 17 2010 11:39 AM

Dan, you had better call Joseph D"Aleo and talk. Somebody is being very misleading.

12 Facts about Global Climate Change That You Won’t Read in the Popular Press
By Joseph D’Aleo
Posted on Aug. 18, 2008

1 Temperatures have been cooling since 2002, even as carbon dioxide has continued to rise.
2 Carbon dioxide is a trace gas and by itself will produce little warming. Also, as CO2 increases, the incremental warming is less, as the effect is logarithmic so the more CO2, the less warming it produces.

3 CO2 has been totally uncorrelated with temperature over the last decade, and significantly negative since 2002.

4 CO2 is not a pollutant, but a naturally occurring gas. Together with chlorophyll and sunlight, it is an essential ingredient in photosynthesis and is, accordingly, plant food.

5 Reconstruction of paleoclimatological CO2 concentrations demonstrates that carbon dioxide concentration today is near its lowest level since the Cambrian Era some 550 million years ago, when there was almost 20 times as much CO2 in the atmosphere as there is today without causing a “runaway greenhouse effect.”

6 Temperature changes lead, not lag, CO2 changes on all time scales. The oceans may play a key role, emitting carbon dioxide when they warm as carbonated beverages lose fizz as they warm and absorbing it as they cool.

7 Most of the warming in the climate models comes from the assumption that water vapor and precipitation increase as temperatures warm, a strong positive feedback. Water vapor is a far more important greenhouse gas than CO2. However, that assumption has been shown in observations and peerreviewed research to be wrong, and in fact water vapor and precipitation act as a negative feedback that reduces any small greenhouse warming from carbon dioxide.

8 Indeed, greenhouse models show the warming should be greatest at mid to high atmosphere levels in the tropics. But balloon and satellite observations show cooling there. The greenhouse signature or DNA does not match reality, and the greenhouse models thus must greatly overstate the warming – and in a court of law would have to be acquitted of any role in global warming

9 The sun has both direct and indirect effects on our climate. Solar activity changes on cycles of 11 years and longer. When the sun is more active it is brighter and a little hotter. More important though are the indirect effects. Ultraviolet radiation increases much more than the brightness and causes increased ozone production, which generates heat in the high atmosphere that works its way down, affecting the weather. Also, an active sun diffuses cosmic rays, which play an important role in nucleation of low clouds, resulting in fewer clouds. In all these ways the sun warms the planet more when it is active. An active sun in the 1930s and again near the end of the last century helped produce the observed warming periods. The current solar cycle is the longest in over 100 years, an unmistakable sign of a cooling sun that historical patterns suggest will stay so for decades.

10 The multidecadal cycles in the ocean correlate extremely well with the solar cycles and global temperatures. These are 60 to 70 year cycles that relate to natural variations in the largescale circulations. Warm oceans correlate with warm global temperatures. The Pacific started cooling in the late 1990s and it accelerated in the last year, and the Atlantic has cooled from its peak in 2004. This supports the observed global land temperature cooling, which is strongly correlated with ocean heat content. Newly deployed N.O.A.A. buoys confirm global ocean cooling.

11 Warmer ocean cycles are periods with diminished Arctic ice cover. When the oceans were warm in the 1930s to the 1950s, Arctic ice diminished and Greenland warmed. The recent ocean warming, especially in the 1980s to the early 2000s, is similar to what took place 70 years ago and the Arctic ice has reacted much the same way, with diminished summer ice extent.

12 Antarctic ice has been increasing and the extent last year was the greatest in the satellitemonitoring era. We are running ahead of last year’s record pace.

What will it take for the media to let go of their biases and begin doing their job, reporting the truth?

Joseph D’Aleo is executive director of Icecap.

Dan LashofSep 17 2010 11:53 AM

The investment bank Deutsche Bank Climate Advisors asked Columbia University's Earth Institute to look carefully at these claims. Their report is an excellent resource. See:

Comments are closed for this post.


Switchboard is the staff blog of the Natural Resources Defense Council, the nation’s most effective environmental group. For more about our work, including in-depth policy documents, action alerts and ways you can contribute, visit

Feeds: Dan Lashof’s blog

Feeds: Stay Plugged In