A provocative Calgary group says it has posted a billboard message in Alberta saying that global warming ended naturally and the Earth is cooling.
The group, Friends of Science Society, had earlier this month put up a billboard in Calgary blaming the sun for climate change.
"Global Warming Stopped Naturally 16+ Years Ago," the latest billboard message says.
On its website, Friends of Science has a graph indicating that satellite data show that temperatures in the troposphere (the lowest layer of Earth's atmosphere) haven't risen in the past 16 years, even though carbon dioxide levels keep increasing.
The group has long cast doubt on global warming science. In 2009, it ran a radio advertising campaign in 15 cities, with a similar message, that global warming stopped at the turn of the century and that the sun is the main factor in climate change.
Scientists have indeed noticed a flattening in the worldwide temperature increase in the past 10 to 16 years.
A study released last year attributes that dampening trend to the impact of a climate pattern known as the Pacific Decadal Oscillation.
A cooling phase in the waters of the Pacific Ocean that began just after 1998 explains the hiatus in global warming, according to the study by the Scripps Institution of Oceanography of the University California, San Diego.
In Canada, federal government researchers say the climate is changing and will create more extreme weather.
"On average, warmer temperatures and more rainfall are expected for the country as a whole, with increases in extreme heat and heavy rainfall events, and declines in snow and ice cover," says a report this year by researchers from Natural Resources Canada.
The study notes that average temperatures in Canada rose by 1.5 C between 1950 and 2010.
Friends of Science has made headlines before.
The group has in the past received donations from Talisman Energy, but the Calgary oil firm has since distanced itself.
Talisman says its 2004 donations were the decision of past management and that it is committed to reduce its carbon footprint to help solve climate issues.
Another past source of funding for Friends of Science were two research accounts at at the University of Calgary, according to a 2008 school internal audit.
Brendan DeMelle, executive director of DeSmogBlog, a climate change website, said Friends of Science are fighting a rearguard action when most scientists and even most of the energy industry has come to accept climate science.
"These billboards are a clear indication of their increasingly desperate effort," Mr. DeMelle said.