CO2 Levels Reach 400ppm at Mauna Loa For First Time On Record

Titus Andronicus writes "Today, NOAA reported, 'On May 9, the daily mean concentration of carbon dioxide in the atmosphere of Mauna Loa, Hawaii, surpassed 400 parts per million for the first time since measurements began in 1958.' For comparison, over the last 800,000 years, CO2 has ranged from roughly 180 ppm to 280 ppm. 'For the entire period of human civilization, roughly 8,000 years, the carbon dioxide level was relatively stable near that upper bound. But the burning of fossil fuels has caused a 41 percent increase in the heat-trapping gas since the Industrial Revolution, a mere geological instant, and scientists say the climate is beginning to react, though they expect far larger changes in the future.' The last time Earth had 400 ppm was probably more than 3 megayears ago."

Comments

Re:queue the denialists!

[rusty0101]

As pointed out by Lionel Dricot at http://ploum.net/post/the-cost-of-being-convinced, there is a cost of changing your position. A large number of climate deniers have invested themselves in the position they have taken, and unless they can find a benefit to changing their position that outweighs the investment they have made, they are likely to stand firm in their state of denial.

Potentially a far more useful technique, than bashing them over the head with the facts, is to start by having them review the facts surrounding the level of CO2 in the atmosphere, and then ask them to provide proposals as to why those levels have changed in the timeframe they have. That engages them in the process of actually doing science, as once they have proposed a hypothesis as to what may be causing an increase in CO2, those hypotheses can be tested. (I.e. it's the destruction of the rainforest - what does satellite data show about the circulation of O2 generated in the rainforest? It tends to stay in the area of the rainforests. Volcanoes emit CO2! Have we seen a tremendous increase in volcanic activity in the past century? No. Etc.) Start getting them to invest in looking at possibilities that can be tested, rather than having them try to change their minds based on decisions they have invested in.

Nah, it probably won't work, but it seems to me to be better than trying to sit and debate the topic with people who've come to the table already decided that no matter what the logic of proof that's provided, they are not going to change their position.

Re: Why not? This proves Warmists are wrong.

[dryeo]

Interesting, I hadn't thought about soil erosion. What I was thinking about was rock weathering where CO2 is consumed by silicate weathering which results in calcium carbonate. This page shows it pretty well, http://dilu.bol.ucla.edu/home.html. There are vast amounts of carbon sequestered as calcium carbonate, maybe half that has ever been released from the mantle. Wiki mentions that erosion also transports dissolved CO2 to the ocean where various organisms convert it to calcium carbonate, think shells falling to the bottom of the ocean to form limestone.
In geological time frames this has a large impact on global climate. When the continents are in one mass there is little rainfall in the interior and little erosion. Global CO2 levels increase along with temperature. And the opposite also happens, lots of continents, especially with mountain ranges in the right places so lots of rainfall on land causing erosion and CO2 levels go down. This is perhaps the current situation.