Most North Americans know that human-caused global warming is real, even if political leaders donB次元官网网址檛 always reflect or act on that knowledge.
According to a recent poll, only two per cent of Canadians reject the overwhelming scientific evidence that Earth is warming at alarming rates B次元官网网址� a figure that may seem surprising given the volume of nonsense deniers (many of them funded by the fossil fuel industry) spread through letters to the editor, blogs, radio call-ins, and website comments.
Polling indicates more deniers live in the U.S., but they still make up just 15 per cent of that population.
ItB次元官网网址檚 getting harder to ignore the evidence: record high worldwide temperatures; increasing extreme weather events; devastating droughts, floods, and wildfires; animal and plant species turning up where theyB次元官网网址檝e never been found before; record ice loss in the Arctic and Greenland; melting glaciers B次元官网网址� The trends are exactly as climate scientists predicted.
Meanwhile, one of the few skeptic climate scientists, Richard Muller, recently reversed his thinking. Muller and colleagues at the University of California, Berkeley, studied climate data dating back to 1753, then looked at possible causes of the unusual warming observed since the mid-1950s. (Ironically, the study was funded in part by the Charles G. Koch Charitable Foundation, founded by climate change skeptics with heavy interests in the fossil fuel industry.)
Their conclusion? ItB次元官网网址檚 not the sun. ItB次元官网网址檚 not volcanoes. The most likely cause is humans spewing massive amounts of carbon dioxide into the atmosphere, mainly by burning fossil fuels. This isnB次元官网网址檛 news to most climate scientists.
As evidence builds, deniers are starting to change their tune. They once said global warming isnB次元官网网址檛 happening, and some claimed the world is actually cooling.
Now, heat records are being broken worldwide B次元官网网址� this past decade was the hottest on record. Many scientists say the situation is even more severe than first thought, with temperatures and impacts increasing faster than predicted.
Faced with the evidence, many deniers have started to admit that global warming is real, but argue that humans have little or nothing to do with it. MullerB次元官网网址檚 study was just one of many to demolish that theory.
Our climate has always changed, and natural variation is part of that. But scientists have long known that carbon dioxide and other gases trap heat in the atmosphere.
Recent warming is occurring at an unprecedented rate that corresponds to burning fossil fuels.
According to NASA, global average temperatures have been rising significantly since the 1970s, B次元官网网址渨ith the 20 warmest years having occurred since 1981 and with all 10 of the warmest years occurring in the past 12 years.B次元官网网址� North America just experienced the hottest July on record, and the first seven months of 2012 were the warmest, on average, in more than 100 years.
This evidence has caused some deniers to change their tune again. Yes, the Earth is warming, they say, but whether itB次元官网网址檚 from natural or human causes, we canB次元官网网址檛 do anything about it, so we might as well continue with business as usual, maybe employing technological fixes to help us adapt.
ThereB次元官网网址檚 also a subset of deniers who see some nefarious conspiracy in climate science and B次元官网网址淎genda 21B次元官网网址� (a nonbinding, voluntary UN agreement on sustainable development) to impose a world government or something, but their irrational arguments arenB次元官网网址檛 worth the time of day.
The truth is, as most of us know, that global warming is real and humans are major contributors, mainly because we wastefully burn fossil fuels. We also know solutions lie in energy conservation, shifting to renewable sources, and changing our patterns of energy and fuel use.
Scientists have been warning about global warming for decades. ItB次元官网网址檚 too late to stop it now, but we can lessen its severity and impacts.
The side benefits are numerous: less pollution and environmental destruction, better human health, stronger and more diversified economies, and a likely reduction in global conflicts fuelled by the rapacious drive to exploit finite resources.
We can all work to reduce our individual impacts. But we must also convince our political and business leaders that itB次元官网网址檚 time to put people B次元官网网址� especially our children, grandchildren, and generations yet to come B次元官网网址� before profits.
