Dr. Roy Spencer presents the latest measurements of lower troposphere temperature as measured by two sets of satellites. See his post here. He presents a graph showing measured temperatures versus model predictions.

You can see that actual global temperatures have flattened out since about 1998. The “spaghetti” on the graph represents predictions of 44 models and the black line is the average of model predictions.

Spencer presents three possible explanations for the divergence:

“1) the real climate system is not as sensitive to increasing CO₂ as the models are programmed to be.” (His preferred explanation).

“2) the extra surface heating from more CO₂ has been diluted more than expected by increased mixing with cooler, deeper ocean waters (Trenberth’s explanation)”

The oceans have a high heat capacity and can absorb great quantities of heat. But have they? The subject is controversial. Anthony Watts discusses the problem here. He notes a recent study which says that between 1955 and 2010, the temperature of the global ocean, between the surface and a depth of 2,000 meters increased in temperature by 0.09 C. That’s not much and Watts wonders if we can even measure to that precision.

“3) increased manmade aerosol pollution is causing a cooling influence, partly mitigating the manmade CO₂ warming.”

However, a 2007 satellite-based NASA study shows that aerosols have been decreasing steadily since 1992. In particular, sulfate aerosols have been greatly decreasing since establishment of the 1970 Clean Air Act in the U.S. and similar measures in Europe.

Explanations #2 and #3 seem to have problems. That leaves #1: the climate is not very sensitive to carbon dioxide and is much less sensitive than models assume. The forcing effect of carbon dioxide, if any, is apparently easily overcome by stronger natural forces.

If Spencer’s first explanation is correct, the political war on fossil fuel emissions is futile and will have little or no effect on global temperatures, but that war will cost us dearly by raising energy prices and making our electric grid less reliable.

See also:

Global warming theory fails again

Failure of the Anthropogenic Global Warming Hypothesis

We keep hearing in the press that the year 2010 has been the hottest ever, or at least hottest since 1880, or at least hottest since it’s been cooler. That claim is partially the result of cherry-picking data and even manufacturing data with sophisticated computer programs that “invented” weather stations where none exist.

Here is some real data, from NOAA High Plains Regional Climate Center, of temperature departure from normal for January 1, 2010 through July 31, 2010. It shows that the northeast U.S. has been warmer than normal, but about 60% of the U.S. has had temperatures below normal.

Source: http://www.hprcc.unl.edu/products/maps/acis/YearTDeptUS.png

In the Arctic, spring sea ice melting got a late start, then melted faster than normal, and now has returned to a normal rate (see red line in graph below).

Source: http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

From Dr. Roy Spencer at UAH: “Sea Surface Temperatures (SSTs) measured by the AMSR-E instrument on NASA’s Aqua satellite continue the fall which began several months ago. The following plot, updated through July 29, 2010 shows that the cooling in the Nino34 region in the tropical east Pacific continue to be well ahead of the cooling in the global average SST, something we did not see during the 2007-08 La Nina event.

Spencer’s graph of atmospheric temperatures, based on satellite readings, show that 2010, an El Nino year, is warmer than the 1979-2001 average, but still cooler than 1998, also an El Nino year:

Abundant research shows that the Medieval Warm Period, ca. 1100 to 1300 A.D. was about 6 degrees F warmer than now (see one example here.)

Meanwhile, in the southern hemisphere:

Peru declared state of emergency amid plunging temperatures. Hundreds die from extreme cold in remote mountain villages also struggling with severe poverty. Source UK.Guardian. Brazil, Argentina, and Uruguay experience extreme cold. In Bolivia, tropical areas temperatures plummeted to zero causing “millions of dead fish” in rivers that normally flow in an environment of 20 Celsius.

Antarctic sea ice extent is greater than normal (Data from National Snow and Ice Data Center in Boulder, Colorado.)

When put into perspective, 2010 is not so hot. Last winter when much of the U.S. experienced very cold weather, climate alarmists dismissed that saying short term weather is not climate. In that they were right. But now since we’ve had a hot June, those same people are using a short-term weather phenomenon to claim that the climate is heating up. The climate has cycles of many different periods from years to centuries to millennia to hundreds of millions of years. Where we are now in these cycles seems to depend on who is doing the measuring and data compilation. Lost in the prognostications and press releases is evidence of causation. In the case of those who say we are experiencing unprecedented warming is the implication that humans are the main cause, but those same people are unable to present any compelling physical evidence to support that contention. Personally, I find the physical geological evidence of natural climate cycles both compelling and sufficient to explain the trends. The contention that this year or this decade is warmer or cooler than some time in the past proves nothing.

Dr. Ross McKitrick has just published “A Critical Review of Global Surface Temperature Data Products,” which goes into great detail about problems with our temperature data sets (73 pages). That paper documents a major reduction in world-wide weather stations since 1970. The remaining stations are skewed toward airport sites, lower latitudes, and lower elevations; each of which produces a warming bias in the data. McKitrick concludes, “The overall conclusion of this report is that there are serious quality problems in the surface temperature data sets that call into question whether the global temperature history, especially over land, can be considered both continuous and precise. Users should be aware of these limitations, especially in policy-sensitive applications.”

For some further perspective see a recent report of a drilling project in Greenland. This project drilled more than 1.5 miles into the ice to investigate “the Eemian interglacial period from about 115,000 to 130,000 years ago, a time when temperatures were 3.6 to 5.4 degrees Fahrenheit above today’s temperatures.” “Ice cores from previous drilling efforts revealed temperature spikes of more than 20 degrees Fahrenheit in just 50 years in the Northern Hemisphere.” So what if the last decade was the warmest since whenever?

Here is a story you won’t see in the Arizona Daily Star.  Three Australasian researchers have shown that natural forces are the dominant influence on climate, in a study just published in the Journal of Geophysical Research. The research finds that finds that the El Niño -Southern Oscillation (ENSO) is a key indicator of global atmospheric temperatures seven months later.

The abstract of the paper says in part: “The results showed that SOI (Southern Oscillation Index) accounted for 81% of the variance in tropospheric temperature anomalies in the tropics. Overall the results suggest that the Southern Oscillation exercises a consistently dominant influence on mean global temperature, with a maximum effect in the tropics, except for periods when equatorial volcanism causes ad hoc cooling. That mean global tropospheric temperature has for the last 50 years fallen and risen in close accord with the SOI of 5–7 months earlier shows the potential of natural forcing mechanisms to account for most of the temperature variation.”

Citation:

McLean, J. D., C. R. de Freitas, and R. M. Carter (2009), Influence of the Southern Oscillation on tropospheric temperature, J. Geophys. Res., 114, D14104, doi:10.1029/2008JD011637.

To see a broader view of natural climate change, see my article: Natural Climate Cycles.