Ice melts every summer
For years, the Science and Public Policy Institute has been drawing public attention to the flimsiness of the alarmist case, both in its popular Scarewatch series and, more recently, in its authoritative and influential Monthly CO2 Reports, which have revealed that the rate of increase in atmospheric CO2 concentration is half the UN's central estimate -
CO2 is rising in a straight line, well below the IPCC's projected range of increases in CO2 concentration (pale blue region). The deseasonalized real-world data are shown as a thick, dark-blue line superimposed on the least-squares linear-regression trend. Data source: NOAA.
Our monthly reports have also revealed that there has been rapid global cooling for seven full years since 2001 -
For the past seven full years, global temperatures have exhibited a pronounced and statistically-significant downtrend. The IPCC's predicted warming path (pink region) bears no relation to the global cooling that has been observed in the 21st century to date. Source: SPPI global temperature index. Data sources: SPPI composite global-temperature anomaly index (top); Hadley Centre; US National Climatic Data Center; Remote Sensing Systems; University of Alabama at Huntsville.
Also, the rate of warming between 1975 and 1998 was no greater than that from 1860-1880 and 1910-1940, from which it follows that there is no detectable anthropogenic influence on temperature at all, and the influence of CO2 on temperature is a great deal less than the UN's climate panel imagines -
No anthropogenic signal is evident in the temperature record of the past 150 years. The warming rate from 1975-1998 is identical to the warming rates from 1860-1880 and from 1910-1940. In the two earlier periods, humankind cannot have had any influence on the warming rate.
Remarkably, the SPPI has now been joined by the United Kingdom's Met Office in sounding warnings about the absurdly extreme predictions that are so routinely and widely but baselessly circulated. The Damascene conversion of the Met Office, known to Margaret Thatcher as the "Wet Office" because of its propensity to predict disasters that fail to materialize, is spectacular.
In mid-February 2009, on the website of The Guardian, usually one of the worst offenders among the alarmist Press, the Met Office Hadley Centre has launched a blistering attack on scientific colleagues and journalists who exaggerate the effects of "global warming".
In an article entitled Scientists must rein in misleading climate-change claims, Dr. Victoria Pope, head of "climate change advice" at the Met Office, says, "News headlines vie for attention and it is easy for scientists to grab this attention by linking climate change to the latest extreme weather event or apocalyptic prediction. But in doing so, the public perception of climate change can be distorted."
Dr. Pope goes on: "Recent headlines have proclaimed that Arctic summer sea ice has decreased so much in the past few years that it has reached a tipping-point and will disappear very quickly. The truth is that there is little evidence to support this. Indeed, the record-breaking losses in the past couple of years could easily be due to natural fluctuations in the weather, with summer sea ice increasing again over the next few years."
Dr. Pope says that headlines of this sort divert attention from "real issues", such as recent Met Office findings that "there is a detectable human impact in the long-term decline in sea ice over the past 30 years, and all the evidence points to a complete loss of summer sea ice much later this century."
In fact, there is no "detectable human impact" on global sea-ice extent, which has exhibited practically no trend in the 30 years since satellites have been available to allow us to calculate it -
The steady, seasonal "heartbeat" of global sea-ice extent: There has been a very slight decline in the trend (red) of global sea-ice extent over the decades, chiefly attributable to loss of sea ice in the Arctic during the summer, which was well below the mean in 2007, with some recovery in 2008. However, the 2008 peak sea-ice extent was exactly on the 1979-2000 mean. The decline in summer sea-ice extent in the Arctic, reflected in the global anomalies over most of the past eight years, runs counter to the global cooling trend over the same period, suggesting that the cause of the regional sea-ice loss cannot have been "global warming". Seabed volcanic activity recently reported in the Greenland/Iceland gap, with seabed temperatures of up to 574 °F, may have contributed to the loss of Arctic sea-ice. Source: University of Illinois.
The Greenland ice sheet, says Dr. Pope, has been used to make claims and counter-claims about the climate: "The melting of ice around south-east Greenland accelerated in the early part of this decade, leading to reports that scientists had underestimated the speed of warming in this region. Recent measurements ... show that the speed-up has stopped across the region. ... Natural variability has been ignored in order to support a particular point of view, with climate change advocates leaping on the acceleration to further their cause and the climate change sceptics now using the slowing down to their own benefit. Neither group is right and all that is achieved is greater confusion among the public."
In fact, the mean thickness of the vast Greenland ice-sheet actually increased at a rate of 2 inches per year in the 11 years 1993-2003 (Johannessen et al., 2005). This rapid and continuing increase in ice thickness scarcely indicates that "global warming" is melting the ice-sheet away, and it more than compensates for the very slight loss of ice in coastal regions over the past 30 years that has reduced the total ice-covered area of Greenland by a tiny fraction of one per cent.
Dr. Pope continues: "For climate scientists, having to continually rein in extraordinary claims that the latest extreme is all due to climate change is, at best, hugely frustrating and, at worst, enormously distracting. Overplaying natural variations in the weather as climate change is just as much a distortion of the science as underplaying them to claim that climate change has stopped or is not happening. ... The implications of climate change are profound and will be severe if greenhouse gas emissions are not cut drastically and swiftly over the coming decades."
Dr. Pope ends by saying: "Our concerns about climate change arise from the scientific evidence that humanity's activities are leading to changes in our climate. The scientific evidence is overwhelming."
Note how carefully worded the last two sentences are. The scientific evidence that human activities are increasing the concentration of CO2 in the atmosphere is indeed overwhelming. However, we know that there was 20 times as much CO2 in the atmosphere in the Cambrian and Triassic eras, when humans cannot have had anything to do with it because we were not there.
Also, the scientific evidence that the additional CO2 in the atmosphere has an appreciable influence on global temperature is by no means overwhelming. Indeed, as the SPPI's Monthly CO2 Reports show, there is nothing unprecedented or unusual about the rate of increase in temperature over the 20th century, or about today's temperatures, which are well below those of the medieval, Roman, and Minoan warm periods, 5 Fahrenheit degrees below temperatures over the past 10,000 years, 10 Fahrenheit degrees below temperatures in each of the past four interglacial periods, and 12.5 Fahrenheit degrees below the median global surface temperature over the past 600 million years. End of scare.
The Science and Public Policy Institute (SPPI) is a nonprofit institute of research and education dedicated to sound public policy based on sound science. Free from affiliation to any corporation or political party, we support the advancement of sensible public policies for energy and the environment rooted in rational science and economics. Only through science and factual information, separating reality from rhetoric, can legislators develop beneficial policies without unintended consequences that might threaten the life, liberty, and prosperity of the citizenry.