Although methane has a 12 yr atmospheric lifespan, it is also produced by volcanic activity not related to life. Also, hydrocarbons are very abundant in the solar system and are not necessarily caused by life/eco systems. Saturn's moon titan has an atmosphere of mostly methane, etc.

 

I didn't get from the article I posted or the NASA article you posted that the revised 17 inch estimate from the UN IPCC only included heat expansion. Do you have specific evidence of this?

The IPCC list "Exchange of water on land by glaciers and ice sheets with ocean water" as a cause of sea level rise.

Here is what the IPCC had to say in the last report about Greenland and Antarctica.

Greenland and Antarctic ice sheets: Most of Earth’s water that is not contained in the oceans is locked up in Greenland and Antarctic ice sheets. The ice sheets, thousands of feet thick at their widest, sit on land. Antarctic temperatures are so cold all year that very little ice actually melts. Antarctica’s ice sheet loses ice when large chunks break off and float away as icebergs, a process given the name "iceberg calving." But, this process can take decades to occur. Greenland’s temperatures, on the other hand, aren’t as cold and its ice sheet is subject to more immediate changes from melting and accumulating snow as well as more frequent iceberg calving. Therefore, climate change is expected to affect Greenland much more than Antarctica. IPCC found that changes in Greenland’s ice sheet, especially around its edges, could raise sea levels about 2.5 inches over the next 100 years. In contrast, a warmer climate is expected to increase the amount of accumulating ice due to snowfall on Antarctica. IPCC projects a sea level drop between 1 and 2.5 inches by the year 2100.

It seems that Antarctica is gaining ice almost as fast as Greenland is losing ice.

The old prediction was between 8-34 inches with 20 most likely from all sources of sea level change.

The report I showed only said the high end estimate dropped from 34 down to 17. My guess is the soon to be released report will be 4-17 inches with 10 inches likely.

 

Titan also has a temperature cold enough to freeze methane and receives only a tiny fraction of the amount of solar radiation the earth does. Both factors make HC lifespan on titan much much longer.

While other activities can produce hydrocarbons such as methane, most methane generated in our atmosphere is generated by life processes itself either through living or decaying process.

If Titan were in Earth orbit, it's methane supplies would have been exhausted a long time ago...assuming life did not occur.

~X~

 

Oops. My mistake. They are including meltwater.

As of 2001, by their own statements, the models used for predicting meltwater were subject to extreme volatility.

I'm not so sure I would take it to that conclusion. Calving has increased in both hemispheres, just not as much on Antarctica. And parts of Antartica are indeed subject to temperatures warm enough to melt ice and snow (now). In the summer, areas near the coast go above freezing. The interior however remains quite cold even during the peak of summer due to it's high elevation.

I'm still waiting for them to get their models up to a higher confidence interval. Well have to wait and see what the new report says when it goes final (in the next few months).

The link I posted indicated that iceberg calving and meltwater may be higher than currently estimated. If the latest models do not include these observations then their models will be off.

It's a constant tuning process. The IPCC should be releasing reports every year, not every five years. They should also keep governments out of it, as they are notorious for pushing their own agendas. It seems that currently their is some controversy over certain governments appointing individuals to the IPCC who may not be the best choices.

~X~

 

When cows start eating coal and oil, I'll worry about their carbon output. Until then, they are just part of a 'net sum zero' carbon game. They start with plant fixed, atmospheric carbon and release it back. This is just cycling the biomass carbon.

The problem is taking carbon that had been locked in coal, oil and methane deposits and adding to the total carbon load.

Bob Wilson

 

I'm with you on this one Bob.

 

So do you mean to say that if we started using algae to power our vehicles (an idea that I support), you would not have a problem with our carbon output?

By the way, coal has many much more real problems than its contribution to CO2 production, such as the radioactive materials released into the air when coal is burned, hurting the environment and consequently, the economy, because the cost of health care sky rockets as a result of the various forms of cancers that result from the radiation emissions of coal burning power plants.

 

No problem at all and would like to see the ponds 'killed' and covered with a nice layer of clay say every 10th year. If the ponds could be located in subduction geological areas, I couldn't be happier. For now, it would be good enough to locate them in areas no more than 1 meter above the current sea level. <GRINS>

Bob Wilson

 

Yes. trees need CO2 but we're cutting down the trees that act as CO2 filters at rates never seen before. The Boreal and Amazon forests are disappearing...so MORE CO2 production + LESS CO2 absorption is a huge, huge problem...and we're behind it 150%.

 

I do not know about the Boreal and Amazon forests, but in 1920, the United States had 735 million acres of forests. Now, the United States only has 749 million acres of forests. If the losses in the Boreal and Amazon forests are anything like the losses in the United States, it is a cause for celebration.