Nature Quote by Elizabeth Kolbert

“at 378 parts per million, current CO2 levels are unprecedented in recent geological history. (The previous high, of 299 parts per million, was reached…

— Elizabeth Kolbert

“Why have global temperatures not risen in the best part of two decades while CO2 levels have kept on rising? •    ”

— Alan Carlin

Each year we pump at least six billion tons of heat-trapping carbon into the innermost layer of our atmosphere, whose outer extent is only…

— Ross Gelbspan

The general trend in the last 4,000 years is that carbon dioxide and temperature have been moving against each other.

— Piers Corbyn

About fifty million years ago...geological evidence indicates CO2 levels were several thousand ppm, much higher than now. And life flourished abundantly.

— William Happer

Weather patterns over the next 20 or 30 years are going to be determined by the amount of CO2 that is up there now

— John Beddington

When I was a boy in the 1930s, the carbon dioxide level was still below 300 parts per million. This year, it reached 382,…

— David Attenborough

By geo-historical standards, today's atmospheric CO2 levels are remarkably - indeed dangerously - low. We need CO2 in the air to support plant growth…

— Roger Helmer

It's likely that CO2 has some warming effect, but real proof of that hypothesis is tricky. You have to confirm by observation exactly how…

— Nigel Calder

The concentration of atmospheric carbon dioxide has changed greatly since fossilized life began on Earth nearly 600 million years ago. In fact, there is…

— Greg Benson

...the contribution of greenhouse gases to the Vostok temperature changes can be...between a lower estimate of 40% and a higher estimate of 65%.

— Claude Lorius

The models that have been constructed agree that when, as has been predicted, the level of carbon dioxide or its equivalent in other greenhouse…

— Bill McKibben