Climate Climate & Energy

Blow and Behold

World’s biggest offshore wind farm given OK in England The world’s biggest offshore wind farm has been given the go-ahead and will soon be built 12 miles off the coast of southeast England. The quaintly named London Array, being developed by a consortium that includes Shell WindEnergy, will consist of 341 turbines. A separate 100-turbine […]

‘Global warming is part of a natural cycle’–This idea is one short step above appealing to magic

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: Current warming is just part of a natural cycle.

Answer: While it is undoubtedly true that there are natural cycles and variations in global climate, those who insist that current warming is purely natural -- or even mostly natural -- have two challenges.

First, they need to identify the mechanism behind this alleged natural cycle. Absent a forcing of some sort, there will be no change in global energy balance. The balance is changing, so natural or otherwise, we need to find this mysterious cause.

Second, they need to come up with an explanation for why a 35% increase in the second most important greenhouse gas does not affect the global temperature. Theory predicts temperature will rise given an enhanced greenhouse effect, so how or why is it not happening?

‘Vineland was full of grapes’–Or was it an early advertising campaign?

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: Newfoundland was so warm in the Medieval Warm Period that when the Vikings landed they called it Vineland and brought boatloads of grapes back to Europe.

Answer: Once again: you can't draw conclusions about global climate from an anecdote about a single region, or even a few regions. You need detailed analysis of proxy climate indicators from around the world. These proxy reconstructions have shown that the Medieval Warm Period (around the time the Vikings are said to have discovered North America) was not as pronounced or as warm as today's warmth. From NOAA's paleoclimate website comes these quotes:

A look back

Here are the first five of my "Top 10 climate stories of 2006," in no particular order.

National Academy hockey stick report: I'm not sure if this helped or hurt the cause, but it did confirm what many scientists already thought: it's hard to figure out the temperature of the earth 1,000 years ago. The IPCC's 2001 report said there was a 3 in 4 chance that the 1990s were the warmest decade, and 1998 the warmest year, of the last 1,000. According to the academy report, subsequent research suggests it's really a 50-50 proposition. In the end, we just don't know whether it was hotter 1,000 years ago or not. None of that, of course, affects our conclusion that humans are warming the climate.

‘The hockey stick is broken’–Well, no … but who’s playing hockey anyway?

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: The Hockey Stick graph -- the foundation of global warming theory -- has been shown to be scientifically invalid, perhaps even a fraud.

Answer: The first order of business here is to correct the mischaracterization of this single paleoclimate study as the "foundation" of global warming theory.

What's going on today is understood via study of today's data and today's best scientific theories. Reconstructions of past temperatures are about, well, the past. Study of the past can be informative for scientists, but it is not explanatory of the present nor is it predictive of the future. The scientific foundation of global warming theory contains much more than a few tree-rings and the temperature during the Medieval Warm Period.

RealClimate has an interesting article about what it would mean for today's climate theories if the MWP had indeed been warmer than today.

Now, about that pesky bit of sporting equipment ...

Yes, the last ice age started thawing over 20,000 years ago, but that stopped a long time ago

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: Global warming has been going on for the last 20,000 years.

Answer: It is true that 20,000 years ago the temperature was some 8 to 10° C colder than it is today. But to draw a line from that point to today and say, "look, 20K years of global warming!" is dubious and arbitrary at best.

If you have look at this graph of temperature, starting at a point when we were finishing the climb out of deep glaciation, you can clearly see that rapid warming ceased around 10,000 years ago (rapid relative to natural fluctuations, but not compared to the warming today, which is an order of magnitude faster). After a final little lift 8,000 years ago, temperature trended downward for the entire period of the Holocene. So the post-industrial revolution warming is the reversal of a many-thousand-year trend.

‘Greenland used to be green’–Don’t judge a book by its cover, much less a land by its name

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: When the Vikings settled it, Greenland was a lovely, hospitable island, not the frozen wasteland it is today. It was not until the Little Ice Age that it got so cold they abandoned it.

Answer: First, Greenland is part of a single region. It can not be necessarily taken to represent a global climate shift. See the post on the Medieval Warm Period for a global perspective on this time period. Briefly, the available proxy evidence indicates that global warmth during this period was not particularly pronounced, though some regions may have experienced greater warming than others.

Second, a quick reality check shows that Greenland's ice cap is hundreds of thousands of years old and covers over 80% of the island. The vast majority of land not under the ice sheet is rock and permafrost in the far north. How different could it have been just 1,000 years ago?

Below is a brief account of the Viking settlement, based on Jared Diamond's "Collapse".

How a grassroots biodiesel group can show the way for others

The way that Rob Del Bueno backed into the world of biofuel almost by accident, as told in the article “Small Potatoes,” is emblematic of the way most folks get engaged in grassroots biofuel development. It starts with a desire to use a renewable fuel to power your life long before a GMO-happy megacorporation was […]

The top 10 reasons to give a hoot about biofuels

Well, here we are, at the end of Grist’s illustrious series on biofuels. We’ve thrown a lot of information at you, and we hope it’s becoming clear why biofuel production is a big, Relevant Thing that deserves your attention. But just in case you need more proof, behold: Grist’s Top 10 Reasons To Give a […]

Unusual Weather We’re Having, Ain’t It?

Number-crunchers say 2006 on track to be the sixth-hottest on record As 2006 limps to a close, it’s measuring in as the world’s sixth-hottest year on record. It’s the warmest Britain has seen since wenches were hoisting tankards of grog (er, since records began in 1659), and the third-warmest in the U.S.’s Lower 48 since […]