Notes from a Warming World: Winter 2013

Temperature Gauge

CO₂ for Dummies

Excess carbon dioxide, we know, is dangerous for the health of the planet’s atmosphere and oceans. Turns out that too much CO₂ can also be bad for the human brain.

A new study finds that excessive indoor carbon dioxide levels impact people’s cognitive abilities. The study, published in Environmental Health Perspectives, evaluated the decision-making and problem-solving abilities of 22 healthy young adults when exposed to increased CO₂. The subjects’ performance dropped notably on six of nine tests when researchers raised a room’s CO₂ level to 1,000 parts per million from a baseline of 600 ppm. Performance fell substantially further when the room’s CO₂ was boosted to 2,500 ppm. The results are surprising, says researcher Roger Hedrick, because “1,000 ppm used to be considered a benchmark for good ventilation.”

Outdoor CO₂ concentrations are often much lower, of course, even though the global numbers continue to climb. This summer parts of the planet measured 400 ppm of CO₂ for the first time in modern history; the global average is currently at 393 ppm. The pre-industrial number hovered around 280 ppm and some scientists, led by NASA climatologist James Hansen, say we need to keep CO₂ concentrations in the 350 ppm range to maintain the planet in a semblance of balance.

The new health study is just more evidence of what we already know: Too much CO₂ is not smart.

From the Archives

Fancy weather satellites, complex computer models, and sophisticated ground level meteorological equipment might be crucial for understanding the climate today and in the future. But there’s nothing like musty old books for learning about the weather of the past.

Climate researchers at the National Oceanic and Atmospheric Administration (NOAA) are enlisting the National Archives and teams of citizen-scientists to help fill a big data gap by transcribing century-old ship logs from the Navy and Coast Guard. The agency is seeking volunteers to transcribe thousands of pages of logbooks from 1850 to World War II. Navy logs include weather observations noted 24 times a day, and the information, once digitized, will help climatologists establish a baseline of historical weather data.

The pages will be scanned and then transcribed by volunteers. Each page will be transcribed three times to eliminate errors. The pages will then be loaded onto oldweather.org. In the first Old Weather project, started in 2010, 16,000 volunteers transcribed 1.6 million weather observations from British Navy ship logs.

“Naval and Coast Guard records are an invaluable window into the past which will let us know what it was like then” NOAA Administrator Jane Lubchenco says.

Small Fry

A nice fish fillet, already in peril because of overfishing, will become even more infrequent in the future as global warming starts to shrink the size of fish.

Warmer ocean temps could make fish smaller.

Warmer water is also less oxygenated, and that means fish are likely to get smaller. Using computer models, researchers looked at 600 species of fish and found that, compared to the year 2000, the maximum body weight of the fish will decline between 14 and 24 percent by 2050 due to warmer waters.

Fish inhabiting the Indian Ocean were the most affected, reducing in size by 24 percent, followed by species in the Atlantic and then the Pacific. Tropical species were hit the worst, according to the projections.

“It’s a constant challenge for fish to get enough oxygen from the water to grow, and the situation gets worse as fish get bigger,” says Daniel Pauly of the University of British Columbia, who first raised the warming-and-growth link 30 years ago.

Ocean acidification due to excess CO₂ in the atmosphere will also impact aquatic species that humans have come to depend on. Shellfish like oysters, clams, and mussels are particularly vulnerable.

Nations that depend on seafood as a source of protein may face more food insecurity as the oceans become warmer and more acidic. According to a report by the environmental group Oceana, the Comoros Islands, Togo, the Cook Islands, Kiribati, and Eritrea are the countries that will be hit hardest by degradation of ocean ecosystems. “Most of the nations that will suffer have done very little to cause climate change,” says Oceana researcher Matthew Huelsenbeck.