It comes from a review of climate data held by meteorologists. They do not investigate the issues of why it is happening, merely summarise the results and confirm the reports of the UN Intergovernmental Panel on Climate Change, which attributes the changes to human activities.

They say that every decade since the 1980s has experienced hotter average global temperatures than the previous one, and that the world has been warming for the last 50 years.

Published by the US National Oceanic and Atmospheric Administration, "The 2009 State of the Climate Report," has been co-authored by 303 scientists from 48 countries, and includes data from last year.
It identifies 10 key global indicators of a warming climate, seven of which should have risen if the climate is warming, and three of which should have fallen – and they all did. They are:

  • Higher temperatures over land
  • Higher temperatures over oceans
  • Higher ocean heat content
  • Higher near-surface air temperatures (temperatures in the troposphere, where Earth's weather occurs)
  • Higher humidity
  • Higher sea surface temperatures
  • Higher sea levels
  • Less sea ice
  • Less snow cover
  • Shrinking glaciers.

The report is copiously referenced to all the data sets used. The data sets are available online interactively for anyone to interrogate.

"Not a single analysis disagrees that the global climate is changing. The bottom line conclusion that the world's been warming is simply undeniable," said Peter Thorne of the Cooperative Institute for Climate and Satellites in Asheville, North Carolina.

Climate sceptics
America is still experiencing attacks from climate change denialists, as the US Environmental Protection Agency last week rejected no less than 10 petitions challenging its report the previous year that greenhouse gas emissions are a danger to human health and the environment.
 
And US Senate Democrats have delayed any possible legislation to curb climate change until September at the earliest. It is now doubtful that there will be any legislation to tackle climate change being passed in America this year.

The energy bill, which also covers offshore drilling and energy security, has been slated for not including sufficiently rigourous measures to curb climate change, by a coalition of environmental groups, such as the Sierra Club. In a statement, they said "There's no doubt that big oil, big coal, their army of lobbyists and their partners in Congress are cheering the obstruction that blocked Senate action on clean energy and climate legislation".

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