World Temperatures Did Not Rise from 1998 to 2008, While Manmade Emissions of Carbon Dioxide from Burning Fossil Fuel Grew by Nearly a Third → Washingtons Blog
World Temperatures Did Not Rise from 1998 to 2008, While Manmade Emissions of Carbon Dioxide from Burning Fossil Fuel Grew by Nearly a Third - Washingtons Blog

Tuesday, July 5, 2011

World Temperatures Did Not Rise from 1998 to 2008, While Manmade Emissions of Carbon Dioxide from Burning Fossil Fuel Grew by Nearly a Third

Reuters notes:

Smoke belching from Asia's rapidly growing economies is largely responsible for a halt in global warming in the decade after 1998 because of sulphur's cooling effect, even though greenhouse gas emissions soared, a U.S. study said on Monday.


World temperatures did not rise from 1998 to 2008, while manmade emissions of carbon dioxide from burning fossil fuel grew by nearly a third, various data show.

The researchers from Boston and Harvard Universities and Finland's University of Turku said pollution, and specifically sulphur emissions, from coal-fueled growth in Asia was responsible for the cooling effect.

Sulphur allows water drops or aerosols to form, creating hazy clouds which reflect sunlight back into space.


Sulphur aerosols may remain in the atmosphere for several years, meaning their cooling effect will gradually abate once smokestack industries clean up.

The study echoed a similar explanation for reduced warming between the 1940s and 1970s, blamed on sulphur emissions before Western economies cleaned up largely to combat acid rain.

"The post 1970 period of warming, which constitutes a significant portion of the increase in global surface temperature since the mid 20th century, is driven by efforts to reduce air pollution," it said.


Other climate scientists broadly supported Monday's study, stressing that over longer time periods rising greenhouse gas emissions would over-ride cooling factors.

The study also argues that natural variables become more significant when man-made warming and cooling (sulfur dioxide) trends cancel each other out:

"Anthropogenic activities that warm and cool the planet largely cancel after 1998, which allows natural variables to play a more significant role," the paper said.

Natural cooling effects included a declining solar cycle after 2002, meaning the sun's output fell.

Indeed, given that scientists now say that the sun may be headed into a lengthy period of low activity, it will be interesting to see how this plays out.

Global warming advocates will point to the portions of the report stating that warming will re-start once China cleans up its coal industry and the low period of solar activity has ended. Global warming skeptics will point to the end of the warming trend despite increased C02 output as disproving mainstream global warming models. One thing is for sure: climate is not a single equation, but a complicated series of interactions between different forces, and - whatever our beliefs on this issue - we should all strive to make sure that we do more good than harm.


  1. The sun. The sun. Hey look up there it's the SUN, and it's responsible for cooling and warming. Right now it's cooling...we even know the mechanism for it. Less solar activity means more cosmic rays, which means more high clouds, which means COOLER temps. Higher solar activity mean fewer cosmic rays hit earth which means few clouds which mean warmer temps.

    Sulfur and carbon make acids that cause acid rain...but their effect on global temp is negligible compared to the SUN. Solar physicists and other guys that can do math tend to disagree with the gas emissions theories of climate change...

  2. Please get in a fight with Max Keiser about Anthropogenic Global Warming.

    I would like to see that.

    I would like to see him lose that.

  3. Well said!

    But the facts and science are irrelevant. This is a political matter aimed at India and China. They will emit massive CO2 as they equalize with the west. It may be a convenient subtext for WAR!

    In the meantime, it will be eventually used to justify trade barriers. If the pols still have control by then. Since they are incompetent they will soon be changed.

  4. Amazing how you quote practically the whole article except this bit:

    "Subsequent years have still included nine of the top 10 hottest years on record, while the U.N. World Meteorological Organization said 2010 was tied for the record."

    Funny how the world can be getting hotter and not getting hotter at the same time.

    And why is that? Why do they choose 1998?

    "A peak in temperatures in 1998 coincided with a strong El Nino weather event, a natural shift which brings warm waters to the surface of the Pacific Ocean every few years."


    "Natural cooling effects included a declining solar cycle after 2002, meaning the sun's output fell."

    So, let's wrap up the WHOLE story shall we?

    In 1998 a record El Nino drove global temperatures into record high territories. By 2008, we had an almost unprecedented solar cooling effect among others and yet last year was TIED with 1998.

    Clearly if you subtract the natural variability, temperatures HAVE increased.

  5. This whole debate hinges on climate sensitivity. There is a large body of evidence pointing to a value of 3 +/- 1.5*C, and a handful of papers pointing to lower values, most of which take a narrow data band to work with.

    It is up to the sceptics to try to avoid refutation of their low CS value.

  6. Indeed, the first sentence of the scientific article reads:

    Given the widely noted increase in the warming effects of rising greenhouse gas concentrations, it has been unclear why global surface temperatures did not rise between 1998 and 2008.

    But if you would read the second and third:

    We find that this hiatus in warming coincides with a period of little increase in the sum of anthropogenic and natural forcings. Declining solar insolation as part of a normal eleven-year cycle, and a cyclical change from an El Nino to a La Nina dominate our measure of anthropogenic effects because rapid growth in short-lived sulfur emissions partially offsets rising greenhouse gas concentrations. would understand that the apparent lack of global warming from 1998 (which was an exceptionally hot year) to 2008 is explained by 1) the solar activity decreasing (as a part of the 11-year cycle of the sun), 2) the exceptionally strong El Niño of 1998 fading, and 3) the short-lived sulphur emissions in China temporarily masking the man-made global warming – indeed, 2010 was the hottest year in recorded history. Solar cycles and El Niños come and go, and as they swing the other way, we'll get a spell of really fast warming.


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