Warming to the science of global warming  

Giles Parkinson at The Climate Spectator has a look at our warming planet - Warming to the science.

It’s getting more difficult to pretend that the world is not warming. A report compiled by the National Oceanic and Atmospheric Administration and involving 300 scientists from 160 research groups in 48 countries is unequivocal: the last decade was the warmest on record and the earth has been growing warmer over the last 50 years.

“The evidence in this report would say unequivocally yes, there is no doubt," that the earth is warming, said Tom Karl, the transitional director of the planned NOAA Climate Service.

This particular report does not analyse the causes of the warning, but defines 10 measurable planet-wide features used to gauge global temperature changes.

Of these, seven indicators are rising: air temperature over land, sea-surface temperature, air temperature over oceans, sea level, ocean heat, humidity and tropospheric temperature in the “active-weather” layer of the atmosphere closest to the Earth’s surface. Three indicators are declining: Arctic sea ice, glaciers and spring snow cover in the Northern hemisphere.

The data was collected from diverse sources, including satellites, weather balloons, weather stations, ships, buoys and field surveys.

Professor Neville Nicholls, of the School of Geography and Environmental Science at Monash University and President of the Australian Meteorological and Oceanographic Society, said the NOAA report confirms not only that the 2000s was the warmest decade in the observational record of global average temperature, but it has also continued into 2010, with the last 12 months the hottest “financial year” on record.

"The warming trends in the satellite and surface thermometer data since 1979 (when the satellite data first became available) have been essentially identical, so don't be fooled by anyone telling you that global warming is caused by the urban heat island effect or problems with thermometers - the satellite data don't suffer from these issues,” Professor Nicholls said. “The NOAA report lists all the many, many data sets available and where you can obtain them. If you have doubts, go and check the data.”

The NOAA report emphasizes that human society which has developed for thousands of years under one climatic state is now facing a new set of climatic conditions are taking shape. Overall, these are warmer, but some areas are likely to witness more extreme events like severe drought, torrential rain and violent storms.

Peter Stott, the head of Climate Monitoring and Attribution of the United Kingdom Met Office Hadley Centre, said there was natural variability year to year, which often reflected natural climatic variations such as El Nino and La Nina, but longer term records and multiple data sets showed “clear and unmistakable” signs of a warming world

“The temperature increase of one degree Fahrenheit over the past 50 years may seem small, but it has already altered our planet,” said Deke Arndt, co-editor of the report and chief of the Climate Monitoring Branch of NOAA’s National Climatic Data Center. “Glaciers and sea ice are melting, heavy rainfall is intensifying and heat waves are more common. And, as the new report tells us, there is now evidence that over 90 percent of warming over the past 50 years has gone into our ocean.”