Scientists appear to be providing evidence toward warming of the global climate, the questions being asked in the last twenty years is to what amount is caused by human production of CO2 and what level of risk may be associated with any possible changes due to global climate may have.
Climate and humans: the long view
Reasons for why the earth surface temperature can increase
Transfer of heat from the sun to the earth
Heat generated in the earth's core.
extra solar radiation, cosmic rays!
Transfer of heat from the sun to the earth
There are two ways for the sun to transfer energy to the earth. The first looks very obvious is visible Light, the light we see is a very small part of what is called the electro magnetic spectrum, this spectrum starts of from very low energies to very high energy's, most of the direct suns heat humans feel is from infra red radiation, the UV radiation can cause cancer.
The second way is called the solar wind, this is mainly comprised of charged particles (affected by magnetic fields) sometimes there are large solar prominences (cause sun spots) that give off very large bursts of energy. The earth is normally protected from these due to its magnetosphere
There is a lot of hype right now about power blackouts etc due to possible leaks in the earth's field in 2012, but what is of interest is the charge particle energy transfer rates and how they vary as the two fields interact and what affect this energy has on the earth temperature ?
Heat generated in the earth's core
Some research indicates that there is 0.09watts per square metre heating from the earth's core mainly due to hot spots in the ocean crust.
There is also hype over the way the earth's core works and there may/may not be a large fission reactor at it centre, A concern is the apparent exponential growth found in the number of thermal vents in the Pacific ocean and the higher temperatures of some of the vents being found, how much overall effect is this having on ocean temperature? and these vents produce large amounts of CO2 how is this affecting the oceans ability to sink man made CO2?
Extra solar radiation, cosmic rays!
The normal amount of energy radiation from outside our solar system as far as scientist know has a very small affect on earth(at least in the short time we have known about it). There are some amazing 'mind blowing' energetic events in our own galaxy the 'Milky Way' let alone in the more distant universe; that if one event happened anywhere near us the massive amount of energy released towards our solar system is not worth thinking about. Most apparently benign cosmic rays constantly flooding our atmosphere all the time are normally absorb by the earth's atmosphere itself or can even pass right through the earth, those that do get absorbed some scientist claim may affect the cloud cover but currently the affect appears to be low enough to not be proven. Interestingly currently there is no proven upper theoretical limit to the amount energy that even a single photon or particle can carry, Fortunately the higher the energy the rarer they are, see over 1020 eV "Ultra-High Energy Cosmic Rays" (UHECR) research. Only time and research will prove their possible affects.
POLITICAL
Comment on Copenhagen
The degree of risk of the additional man-made CO2 production needs to be addressed with respect to other global issues at dangerous levels.
What is most dangerous in the "Copenhagen Treaty" are the political overtones which MUST be addressed, is the world government proposed in the treaty giving enforceable powers to raise taxes globally to an unelected and unaccountable body the right way to move forward?
The Copenhagen treaty wants to cut CO2 emissions by a 50% goal in 2050, This goal could be met from Fusion power stations alone before that date if the political will and funds were in-place.
We have seen in the past during wartime in 1941-5 that given the vastly more taxing at the time "Manhattan project" to make a nuclear bomb with the political will of the USA alone achieved this in just 4 years.
The idea to cooperatively design and build a demonstration fusion reactor originated from a Geneva superpower summit way back in November 1985 when Soviet Premier Gorbachev proposed to President Reagan that an international project be set up to develop fusion energy for peaceful purposes as opposed to "starwars" research in the USA. even after this agreement of U.S. participation in the initial design activity, there was a hiatus, the U.S. only joined the ITER negotiations in early 2003. 6 years later, all we have to show so far is some concrete and a building site in Cadarache (France) and big wrangles over funding causing yet more delays.
The total amount of the US spend in 2009 on the test ITER fusion reactor $124,000,000 (FY 2010 Cong FES Budget) will the Copenhagen treaty do something about this and give some real global political will, unfortunately no.
Comment
If we accept that the earth is in a global warming phase (weather natural or man made) what risks are there?
The Earth's climate and ecology are continually changing as do risks change, Will this current trend be positive or negative to mankind?
Most climate change activists like to point to some form of climate Armageddon yet would a temperature increase be bad? could it be even be beneficial to have warmer temperatures. What ever happen to the climate even if it was to stay the same there is a set of risks to humanity. If desert areas are used to better affect then the extra food that may be possible to grow in the more temperate climes in the north and south.