July 30, 2012

Berkeley Earth Project Says Carbon Dioxide is Cause of Global Warming

Fight disinformation: Sign up for the free Mother Jones Daily newsletter and follow the news that matters.

I promised to link to Richard Muller’s latest climate change paper from the Berkeley BEST group when it was posted on Monday, and it’s now Monday. So here it is. Previous BEST papers have confirmed dramatic global warming over the past century, and the new paper is mostly an attempt to figure out what caused the warming. The answer, unsurprisngly to most of us, is human activity:

Many of the changes in land-surface temperature follow a simple linear combination of volcanic forcing (based on estimates of stratospheric sulfate injection) and an anthropogenic term represented here by the logarithm of the CO2  concentration….When we included solar forcing we found that the solar variability record assumed by the IPCC did not contribute significantly to the fit of historic temperature.

….After accounting for volcanic and anthropogenic effects, the residual variability in land-surface temperature is observed to closely mirror and for slower changes slightly lead variations in the Atlantic Multidecadal Oscillation Index. This is consistent with both the land and North Atlantic responding [to] the same unknown process….Though non-trivial, this number is small compared to the anthropogenic changes that appear to have occurred during the last century.

In English, this means that (a) volcanoes cause short-term spikes in the climate record, (b) changes in solar activity have virtually no effect, and (c) periodic oscillation in North Atlantic sea temperatures accounts for some of the variability we see in the temperature record. However, the primary cause of warming since 1800 is anthropogenic. That is to say: humans did it. Carbon dioxide has produced virtually all of the warming that we see around us today, at the rate of about 3.1 degrees C for every doubling of atmospheric CO2. The chart below shows the close match between CO2 levels, volcanic activity, and surface temperature.

This is pretty much the same result produced by the IPCC and the consensus of every climate scientist working today. The skeptics dived into the data, crunched it in an entirely different way, and came up with the same result: Global warming is real and human activity causes it.

WE CAME UP SHORT.

We just wrapped up a shorter-than-normal, urgent-as-ever fundraising drive and we came up about $45,000 short of our $300,000 goal.

That means we're going to have upwards of $350,000, maybe more, to raise in online donations between now and June 30, when our fiscal year ends and we have to get to break-even. And even though there's zero cushion to miss the mark, we won't be all that in your face about our fundraising again until June.

So we urgently need this specific ask, what you're reading right now, to start bringing in more donations than it ever has. The reality, for these next few months and next few years, is that we have to start finding ways to grow our online supporter base in a big way—and we're optimistic we can keep making real headway by being real with you about this.

Because the bottom line: Corporations and powerful people with deep pockets will never sustain the type of journalism Mother Jones exists to do. The only investors who won’t let independent, investigative journalism down are the people who actually care about its future—you.

And we hope you might consider pitching in before moving on to whatever it is you're about to do next. We really need to see if we'll be able to raise more with this real estate on a daily basis than we have been, so we're hoping to see a promising start.

payment methods

WE CAME UP SHORT.

We just wrapped up a shorter-than-normal, urgent-as-ever fundraising drive and we came up about $45,000 short of our $300,000 goal.

That means we're going to have upwards of $350,000, maybe more, to raise in online donations between now and June 30, when our fiscal year ends and we have to get to break-even. And even though there's zero cushion to miss the mark, we won't be all that in your face about our fundraising again until June.

So we urgently need this specific ask, what you're reading right now, to start bringing in more donations than it ever has. The reality, for these next few months and next few years, is that we have to start finding ways to grow our online supporter base in a big way—and we're optimistic we can keep making real headway by being real with you about this.

Because the bottom line: Corporations and powerful people with deep pockets will never sustain the type of journalism Mother Jones exists to do. The only investors who won’t let independent, investigative journalism down are the people who actually care about its future—you.

And we hope you might consider pitching in before moving on to whatever it is you're about to do next. We really need to see if we'll be able to raise more with this real estate on a daily basis than we have been, so we're hoping to see a promising start.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate