Were dinosaurs wiped out by Global Warming?

Well, no. The theory still stands that dinosaurs disappeared because a large asteroid collided with Earth. But several other mass extinctions tens or hundreds of millions of years ago may have been due to greenhouse gases making the planet too hot.

I want to share with you information from an article by in Scientific American about a new theory that Global Warming killed off large portions of life on Earth – animals and plants on both land and sea – and that it happened more than once. It could happen again, if the oceans get too hot.

The theory is that extensive volcanic activity threw out enormous amounts of CO2 and methane. These greenhouse gases then caused rapid and intense Global Warming. As the oceans heated up they were less able to absorb oxygen, which destabilized the “chemocline” between the oxygen-filled surface and the bottom of the ocean, where little purple and green bacteria produce hydrogen sulfide. The poisonous H2S rose to the ocean’s surface and displaced the oxygen, suffocating sea life. It then rose into air, causing massive death on land. Then, just to finish things off, the H2S moved up into the atmosphere, attacking the ozone shield and allowing ultraviolet rays to add to the destruction below. Nice.

Many millions of years ago
This is believed to have happened at least twice – about 250 million years ago at the end of the Permian period and 50 million years ago at the end of the Triassic period. There is also some reason to believe warming caused other extinctions, including a minor one at the end of the Paleocene era, 54 million years ago.

In the Permian and Paleocene periods, we know that CO2 in the atmosphere increased to about 1,000 parts per million. Today we are at about 385 ppm, with predictions for a rapid increase. If Global Warming isn’t curtailed, we’re heading for 900 ppm by the end of the next century.

During the mass extinctions, the majority of life was destroyed and it took thousands, perhaps millions, of years for it to be replenished. Permian, the largest extinction, took out 90% of ocean dwellers and 70% of plants, animals and insects on land.

This is not sci fi
What takes this out of the realm of science fiction and makes it a scientific theory is that there is evidence to back it up.

Biomarkers in ocean sediment and rocks show chemical evidence of an ocean-wide bloom of H2S-consuming bacteria. And carbon isotope records confirm that CO2 concentrations skyrocketed immediately before the start of the extinctions and stayed high for hundreds of thousands to several million years.

Fossil analysis shows the Permian and Triassic extinctions were drawn-out processes spanning hundreds of thousands of years. And new carbon isotope evidence suggests the biosphere suffered a long series of environmental hits rather than a single, cataclysmic event coming from outer space, where there is sudden die-off and rapid recovery.

So when a non-believer, like Sen. Ted Stevens (R-Alaska), says, sure, there is Global Warming, but it has been a lot warmer in the distant past, you can say yes, it has been, but it wiped out most of the life on Earth.

If you want to read the whole article, by Peter D. Ward, find it at www.sciam.com/issue.cfm?issueDate=Oct-06. The title is “Impact from the Deep.”


Congressional round-up

• The House voted Thursday to roll back $6 billion in oil industry tax breaks, set a fee for deep water drilling in the Gulf of Mexico and recoup royalties lost to the government because of a mistake. The vote was 264-163. Democrats said the bill could raise $14 billion, mostly for alternative energy. The bill is expected to have a tougher time passing the closely divided Senate. The president opposes it.

• The Sanders-Boxer bill, the “gold standard” according to co-sponsor Sen. Barbara Boxer (D-Calif.), calls for cutting GHG 80% by mid-century. Its goal is to stabilize CO2 in the atmosphere by capping emissions at 1990 levels by 2020 and increase cuts each year until 2050. It lets the EPA require further cuts if global CO2 concentrations exceed 450 ppm. Co-sponsor is Sen. Bernie Sanders (I-Vt.). This bill has the support of many environmental groups.

• Sens. Joe Lieberman (I-Conn.) and John McCain (R-Ariz.) reintroduced their Climate Stewardship Act mandating reductions in CO2 emissions across all sectors. It calls for stabilization at 2000 levels and would gradually lower the cap to one-third of 2000 levels by 2050. It allows trade of carbon credits, including borrowing and offsets, to ease the cost of meeting regulations. Some environmental groups say it doesn’t go far enough and encourages nuclear energy.

• Sen. Diane Feinstein (D-Calif.) introduced the first of five energy bills. This one would cut emissions from power plants. It would create a cap-and-trade system and would limit CO2 emissions to 75% of projected 2020 levels. She has the support of 6 power companies.

• Sen. Boxer introduced two bills to increase use of cellulosic ethanol and fuel-efficient motor vehicles. The first asks for $1 billion for R&D and $1 billion for infrastructure to sell the ethanol. The second bill tells the government to buy fuel-efficient fleet cars. Boxer, chair of the Environment and Public Works Committee, plans hearings on Global Warming Jan. 30.

• House Speaker Nancy Pelosi (D-Calif.) set up a select committee on Global Warming to emphasize the issue’s importance. The move was seen by some as a push to House Energy Chair John Dingell (D-Mich.), whose support of the auto industry is a concern. Dingell said he will hold hearings and has invited former Vice President Al Gore to testify. Pelosi wants all committees to bring climate change legislation to the floor by July 4.

• A new coalition of Evangelical Christian leaders and prominent scientists went to Washington last week to ask for action to stop Global Warming.
(Sources: Greenwire, Environment and Energy Daily, E&E Daily PM and AP)

News briefs

1. Last year was warmest in United States history
The average temperature in 2006, in the continental 48, is the warmest on record, according to NOAA. The average was 55 degrees, 2.2 degrees F above the mean for the 20th century and .07 degrees above the previous record, in 1998. The past 9 years were all in the hottest 25 recorded. Worldwide, 2006 was the sixth warmest, according to the United Nations. Last year also set the record for wildfires in the United States. (Sources: E&E News PM, AP)

2. Corporations join in call for strict emissions limits
10 big companies, including GE, DuPont and Caterpiller, are expected to call Monday for a firm limit on carbon dioxide emissions that would result in a cut of 10% to 30% from current levels in 15 years. They will ask that government action include a cap-and-trade system and that no new plants be built that can’t easily capture and store carbon. Other companies in the coalition are Alcoa, BP, Duke Energy, FPL, Lehman Brothers, PG&E and PNM Resources. Environmental Defense, Natural Resources Defense Council, Pew Center on Global Climate Change and World Resources Institute are working with them. (Source: New York Times)

3. State of the Union speech to address Global Warming
President Bush is expected to speak about Global Warming in his State of the Union speech Tuesday, but he will disappoint British officials who were hopeful he might agree to mandatory caps on emissions. The White House said he won’t, and still favors voluntary steps, but that he will encourage the development of alternative fuels like hydrogen and ethanol. Prime Minister Tony Blair met last month with the president, hoping to get an agreement on climate change before Blair leaves office. (Sources: League of Conservation Voters, Greenwire)

4. Doomsday Clock moves ahead; climate change cited
Because of climate change and global nuclear instability, the minute hand of the Doomsday Clock was moved two minutes ahead and now rests at 5 minutes to midnight. It hasn’t been that close since the Cold War. This is the first time climate change was included as a specific threat to civilization. The scientists who made the decision said climate change is second only to nuclear annihilation as a threat to humanity. (Source: BBC News.com)

5. Sweden aims to eliminate fossil fuels by 2020
The Swedish government has plans to increase renewable energy from its current 26% and up its use of biofuels, in order to phase out fossil fuels in the next 13 years. Last year new cars running on alternative fuels increased to 15% from 1%, in part because of government incentives. Some cars run on subsidized methane, made from garbage, which is cheaper than gasoline. (Source: Greenwire)

6. Bears delay hibernation because of hot temperatures
Also in Sweden, bears at a safari park put off starting hibernation from the usual October till December because of record-high temperatures in the southern part of the country. In an unrelated story, Swedish scientists have developed navigational technology that plots the “greenest” route for cars to take, avoiding stoplights, traffic and high speed limits. Initial tests show the system can cut fuel consumption by 8.2%. (Source: Greenwire)


Do something

The League of Conservation Voters has set up a new Web site, www.heatison.org. Check it out. And for now, you can help by signing their petition to all candidates to make Global Warming a priority.