Arguments
What has global warming done since 1998?
What the science says...
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Every part of the Earth's climate system has continued warming since 1998, with 2015 shattering temperature records. |
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Climate Myth...
It hasn't warmed since 1998
For the years 1998-2005, temperature did not increase. This period coincides with society's continued pumping of more CO2 into the atmosphere. (Bob Carter)
Even if we ignore long term trends and just look at the record-breakers, 2015, 2014, 2010, and 2005 were hotter than 1998.
The myth of no warming since 1998 was based on the satellite record estimates of the temperature of the atmosphere. However, as discussed in the video below by Peter Sinclair, even that argument is no longer accurate. The satellites show warming since 1998 too.
There's also a tendency for some people just to concentrate on atmospheric or surface air temperatures when there are other, more useful, indicators that can give us a better idea how rapidly the world is warming. More than 90% of global warming heat goes into warming the oceans, while less than 3% goes into increasing the atmospheric and surface air temperature. Records show that the Earth has been warming at a steady rate before and since 1998 and there is no sign of it slowing any time soon (Figure 1).
Figure 1: Land, atmosphere, and ice heating (red), 0-700 meter ocean heat content (OHC) increase (light blue), 700-2,000 meter OHC increase (dark blue). From Nuccitelli et al. (2012).
Even if we focus exclusively on global surface temperatures, Cowtan & Way (2013) shows that when we account for temperatures across the entire globe (including the Arctic, which is the part of the planet warming fastest), the global surface warming trend for 1997–2015 is approximately 0.14°C per decade.
Ultimately, every part of the Earth's climate system is warming, and has continued warming since 1998.
Last updated on 29 September 2017 by dana1981. View Archives
It is unclear how the calculation at 15 was made. NOAA data is available at LINK and Hadley data at http://www.cru.uea.ac.uk/cru/data/temperature/hadcrut3gl.txt . These both show a trend of about +0.1 degree per decade. Although short term trends can be misleading, like the 22 year run up from 1976 to 1998, the dramatic drop of global average temperature in 2008 may be indicative of a change in character of the climate. The current UAH satellite numerical data (these data consist of the differences of lower atmospheric temperature from the 1979 thru 1998 average) is at http://vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc.lt . According to these data, the AVERAGE GLOBAL TEMPERATURE for the first 9 months of 2008 is LOWER than the average from 2000 thru 2007 by an amount equal to 43.1% of the total linearized increase (NOAA data) during the 20th century. Since 2000, the CARBON DIOXIDE LEVEL HAS INCREASED by 14.4% of the total increase since the start of the Industrial Revolution.
Ocean temperature has decreased since 2003. See R.A. Pielke, Sr., Physics Today, 94, Nov. (2008). which contains this graph: LINK
Actually, the oceans have been warming since 2003. Observations of upper ocean heat show some short term cooling but measurements to greater depths (down to 2000 metres) show a steady warming trend:
However, the ocean cooling myth does seem to be widespread so I'll shortly update this page to clarify the issue.
Look at this link for information on global warming stagnation since 2002: LINK The site is run by Ole Humlum, Professor of Physical Geography at the Department of Geosciences, University of Oslo. He says that "all five global temperature estimates presently show stagnation, at least since 2002. There has been no increase in global air temperature since 1998, which was affected by the oceanographic El Niño event. This does not exclude the possibility that global temperatures will begin to increase again later. On the other hand, it also remain a possibility that Earth just now is passing a temperature peak, and that global temperatures will begin to decrease within the coming 5-10 years. Only time will show which of these possibilities is the correct."
"Did global warming stop in 1998?" Did global warming START in 1998? U.S. Data Since 1895 Fail To Show Warming Trend LINK WASHINGTON, Jan. 25— After examining climate data extending back nearly 100 years, a team of Government scientists has concluded that there has been no significant change in average temperatures or rainfall in the United States over that entire period. While the nation's weather in individual years or even for periods of years has been hotter or cooler and drier or wetter than in other periods, the new study shows that over the last century there has been no trend in one direction or another. The study, made by scientists for the National Oceanic and Atmospheric Administration was published in the current issue of Geophysical Research Letters. It is based on temperature and precipitation readings taken at weather stations around the country from 1895 to 1987. ...
Actually, the new ocean temperature buoy system (ARGO) does show that it's the sea that is storing up heat. The following is the measurement of ocean heat measured by ARGO down to 2000 metres deep and shows the oceans are steadily accumulating heat (von Schuckmann 2009):
Apologies for repeating the same graph from my response to comment #40 but it seems repetition is required for this particular argument.