Chart and analysis adopted from giss nasa

Average mean cloud cover worldwide (1983-2006 over the sea)

Such variations are referred to as “natural” variability, that is the climate varies naturally for reasons that are not fully understood. The problem for understanding climate changes that might be produced by human activities is that the predicted changes are similar in magnitude to those shown here. The difference between natural and human-induced climate change will only appear clearly in much longer ( >= 50 years) data records.

This is exactly what I have been looking for all along. How much is the difference between natural and human-induced climate change? The answer is - we will probably know in about 20 years from now.

Peer reviewed papers of solar science and atmospheric sciences have a hard time to draw any conclusions from solar output, cosmic ray flux, cloud cover and thermohaline circulations that could explain most of the warming of the past 30 years or so (ever since satellite mesurements are available). But I believe it is important that all sides - global warming alarmists, realists, skeptics or even so-called deniers should keep an open mind free from any ideology and funding biases.

Exxon Mobile - again?

Whenever there is a study questioning the magnitude of CO2 as the major driver of global warming, the question of funding arises. In a recent post I mentioned that Exxon Mobile supposedly stopped the funding of media effective think tanks to cast doubts about any influcence of fossil fuels for the climate. Now Greenpeace as a founding member of theExxpose Exxon Coalition published the funding activities of ExxonMobile 2005/2006 here which shows that they reduced the funding and shifted it some. But it accuses the petroleum company of being double faced. While they somehow acknowledge the problem of AGW on their website, the NGO accuses ExxonMobil to continue to fund some of its propaganda strawmen.

How do we know whether there is still a debate going on regarding the amplitude of the greenhouse effect? Let us concentrate on peer-reviewed source papers which do not give any ammunition to global warming turbos as coming from those notorious deniers who are in their eyes obviously funded by ExxonMobile. Even greenpeace states that ExxonMobile is the only left petroleum company who is not willing to invest in renewable energy and who does not even encourage any efforts for the United States to work towards energy independence from the Middle East.

So let us continue to focus on more or less controversal papers that seem to come from reliable sources. Cloud cover is an interesting topic, that I can tell. Stay tuned!