A look at weather extremes and the big-picture climate connections.

When Weather and Climate Gets Cloudy

Repost This

On February 11, the Wall Street Journal posted an op-ed from London-based editorial writer Anne Jolis, about trends in severe weather. She described some preliminary results from the 20th Century Reanalysis Project that look back at indices of climate and weather variability over the past 130 years. The reanalysis project found no significant change to certain broad-scale weather patterns, a fact that Jolis used to contrast with what climate models have predicted for future trends in extreme weather. The words she choose to describe this — “researchers have yet to find evidence of more-extreme weather patterns over the period, contrary to what the models predict" — seem to be aimed at debunking what most climate model projections, and a growing body of detection and attribution studies, show: that climate change increases the odds of certain extreme weather events, and may intensify them as well. 

Jolis, unfortunately, confuses the readers by treating these issues too superficially.

The results from the 20th Century Reanalysis Project, which I also wrote about a few weeks ago, showed that the patterns of three specific climate variability indices hadn’t changed much over the past 130 years, but that doesn’t mean there aren’t any detectable trends in some types of extreme weather. There is more driving weather than just those three climate circulation measures, and many scientific studies have documented changing trends in extreme weather events. Furthermore, con...

Read more...

Risks Keep Rising for Coral Reefs, Analysis Finds

Repost This

Every year, coral reefs off the coast of Florida draw millions of tourists to their vivid undersea colonies of corals, crustaceans, and fish. But rising water temperatures and carbon dioxide-induced ocean acidification, combined with overfishing and pollution, are threatening the survival of these reef ecosystems, scientists say. With more than 90 percent of the species living in Atlantic reefs not found anywhere else in the world, many animals and corals could be lost entirely in the coming years. And if the reefs are lost, or just significantly damaged, the Floridian communities that depend on reef tourism could suffer dramatic economic consequences, standing to lose over $1 billion.   

 

Many of the coral reefs in the Atlantic and Caribbean are threatened by local activities and global climate change. Credit: WRI

According to a new report from the World Resources Institute (WRI), Reefs at Risk Revisited, more than 75 percent of the coral reefs in the Atlantic, including those surrounding Florida, are now threatened by human activities. Though overfishing is the largest single threat to coral reef ecosystems in the area, marine species are becoming more vulnerable to the effects of climate change and high carbon dioxide (CO2) emissions, says the report. 

This morning, NOAA administrator Jane Lubchenco helped launch the new report, which details the current status of the world’s reefs. The analysis draws on a decade of research from over 25 international organizations, and is an updated version of a similar assessment made in 1998.

“This is a critical time for ocean ecosy...

Read more...

Welcome to the Anthropocene

Repost This

There’s nothing like looking at a timeline of Earth’s history to remind oneself that, relatively speaking, humans haven’t been around for very long. But while humans have only roamed the planet for a miniscule fraction of the planet’s 4.5 billion year history, geologists and paleontologists have learned an awful lot about different times in the ancient past. They’ve segmented time on Earth according to major events or changes that took place, such as mass extinctions or beginnings of ice ages. These events created periods of time so distinct that the effects can still be seen in layers of rock today. For example, the past 12,000 years of Earth's history are described as the Holocene epoch.

Scientists say that modern human influence is sending the planet into a new geological epoch — the "Anthropocene." Credit: YiFan Photography/iStock

Now, many scientists insist that recent human activity, beginning about 250 years ago, is having such a significant environmental impact on the Earth’s climate, geography, and biological composition that we have actually entered into a new period of geologic time. That means this change to the “age of man” — or the “Anthropocene” epoch — could be distinctly recognizable when future geologists sift through tiered cakes of rock thousands of years from now.

Nobel prize-winning chemist Paul Crutzen brought the idea of the Anthropocene into the scientific spotlight in 2002 (Crutzen is famous for having studied atmospheric chemistry relating to the hole in the ozone layer), but it is not yet an accepted term in geology vernacular. However, in the March 2011 issue of the P...

Read more...

Permafrost Timebomb

Repost This

For tens of thousands of years, huge amounts of plant matter—roots, leaf fragments and the like—have been kept in cold storage underground in the northern parts of Alaska, Canada, Europe and Siberia. They're embedded in permafrost, or permanently frozen soil. Even when the top few inches of ground thaw out in the Arctic summer, permafrost never does. As the planet continues to warm, however, the "perma" in permafrost is looking less eternal. Scientist have known for years, in fact, that rising temperatures threaten to thaw the permafrost, allowing the plant material to decompose and release carbon dioxide (CO2) into the atmosphere, boosting the effects of CO2 from the burning of fossil fuels.

What they have never known is just how much of that deep-frozen CO2 is likely to emerge. Now, a study in the journal Tellus has provided an answer: by 2200, the extra CO2 could add up to about half as much (allowing for uncertainties) as we've produced through fossil-fuel burning since the dawn of the Industrial Revolution. I talked to the lead author, Kevin Schaefer, about what they learned. 

Global Climate Numbers for January: 17th Warmest on Record

Repost This

Last week we provided you with a run-down of how January 2011 ranked against previous years in terms of average temperatures and precipitation in the U.S.. If you don’t remember the stats — or you’ve managed to block out the memory of how teeth-chattering cold you felt throughout the month — January was colder and drier than average.

Today, NOAA’s National Climatic Data Center (NCDC) released a global analysis of last month's temperatures and precipitation, finding that it was the 17th warmest January on record, with global average combined land and ocean surface temperatures running 0.68°F above the 20th century average.

A map of global temperature departures from average for January 2011. Blue markers indicate areas with below average temperatures; red markers indicate above average temperatures. Credit: NOAA.

The new data also shows the U.S. wasn’t the only country blasted by exceptionally cool air. China experienced their second coldest January, though complete records there only go back to 1961. On the other hand, most of Canada and Siberia — large expanses of land — experienced temperatures well above average, and as mentioned last week, Arctic sea ice extent reached its lowest January extent on record.

Overall, sea surface temperatures last month were the 11th warmest recorded for the month of January. Sea surface temperatures were, however, the warmest they've ever been during January when La Niña conditions were present, indicating that in spite of below average sea surface temperatures throughout the eastern equatorial Pacific, the waters in most other regions of the globe were warm enough to offset the effects of La Niña. La Niñ...

Read more...