I really was just trying to educate and present some real news that is apart from the normal droll of this board. But just so not to avoid the "questions" you guys like to pose, I would offer the following on my way back to the sports' boards
1) The Earth is warming
Global warming is not an output of computer models; it is a conclusion based on observations of a great many global indicators. By far the most straightforward evidence is the actual surface temperature record. While there are places — in England, for example — that have records going back several centuries, the two major global temperature analyses can only go back around 150 years due to their requirements for both quantity and distribution of temperature recording stations.
These are the two most reputable globally and seasonally averaged temperature trend analyses:
NASA GISS direct surface temperature analysis
CRU direct surface temperature analysis
Both trends are definitely and significantly up. In addition to direct measurements of surface temperature, there are many other measurements and indicators that support the general direction and magnitude of the change the earth is currently undergoing. The following diverse empirical observations lead to the same unequivocal conclusion that the earth is warming:
Satellite Data
Radiosondes
Borehole analysis
Glacial melt observations
Sea ice melt
Sea level rise
Proxy Reconstructions
Permafrost melt
There is simply no room for doubt: the Earth is undergoing a rapid and large warming trend.
Sure there are plenty of unsolved problems and active debates in climate science. But if you look at the research papers coming out these days, the debates are about things like why model predictions of outgoing longwave radiation at the top of the atmosphere in tropical latitudes differ from satellite readings, or how the size of ice crystals in cirrus clouds affect the amount of incoming shortwave reflected back into space, or precisely how much stratospheric cooling can be attributed to ozone depletion rather than an enhanced greenhouse effect.
No one in the climate science community is debating whether or not changes in atmospheric CO2 concentrations alter the greenhouse effect, or if the current warming trend is outside of the range of natural variability, or if sea levels have risen over the last century.
This is where there is a consensus.
Specifically, the “consensus” about anthropogenic climate change entails the following:
the climate is undergoing a pronounced warming trend beyond the range of natural variability;
the major cause of most of the observed warming is rising levels of the greenhouse gas CO2;
the rise in CO2 is the result of burning fossil fuels;
if CO2 continues to rise over the next century, the warming will continue; and
a climate change of the projected magnitude over this time frame represents potential danger to human welfare and the environment.
While theories and viewpoints in conflict with the above do exist, their proponents constitute a very small minority. If we require unanimity before being confident, well, we can’t be sure the earth isn’t hollow either.
This consensus is represented in the IPCC Third Assessment Report, Working Group 1 (TAR WG1), the most comprehensive compilation and summary of current climate research ever attempted, and arguably the most thoroughly peer reviewed scientific document in history. While this review was sponsored by the UN, the research it compiled and reviewed was not, and the scientists involved were independent and came from all over the world.
The conclusions reached in this document have been explicitly endorsed by …
Academia Brasiliera de Ciências (Bazil)
Royal Society of Canada
Chinese Academy of Sciences
Academié des Sciences (France)
Deutsche Akademie der Naturforscher Leopoldina (Germany)
Indian National Science Academy
Accademia dei Lincei (Italy)
Science Council of Japan
Russian Academy of Sciences
Royal Society (United Kingdom)
National Academy of Sciences (United States of America)
Australian Academy of Sciences
Royal Flemish Academy of Belgium for Sciences and the Arts
Caribbean Academy of Sciences
Indonesian Academy of Sciences
Royal Irish Academy
Academy of Sciences Malaysia
Academy Council of the Royal Society of New Zealand
Royal Swedish Academy of Sciences
… in either one or both of these documents: PDF, PDF.
In addition to these national academies, the following institutions specializing in climate, atmosphere, ocean, and/or earth sciences have endorsed or published the same conclusions as presented in the TAR report:
NASA’s Goddard Institute of Space Studies(GISS)
National Oceanic and Atmospheric Administration (NOAA)
National Academy of Sciences (NAS)
State of the Canadian Cryosphere (SOCC)
Environmental Protection Agency (EPA)
Royal Society of the United Kingdom (RS)
American Geophysical Union (AGU)
American Institute of Physics (AIP)
National Center for Atmospheric Research(NCAR)
American Meteorological Society (AMS)
Canadian Meteorological and Oceanographic Society (CMOS)
If this is not scientific consensus, what in the world would a consensus look like?
2) Man is the cause
No one credible is arguing that man is the sole cause. However, it is naive at best to somehow convince one's self that man isn't playing a large role. It’s true that natural fluxes in the carbon cycle are much larger than anthropogenic emissions. But for roughly the last 10,000 years, until the industrial revolution, every gigatonne of carbon going into the atmosphere was balanced by one coming out.
What humans have done is alter one side of this cycle. We put approximately 6 gigatonnes of carbon into the air but, unlike nature, we are not taking any out.
Thankfully, nature is compensating in part for our emissions, because only about half the CO2 we emit stays in the air. Nevertheless, since we began burning fossil fuels in earnest over 150 years ago, the atmospheric concentration that was relatively stable for the previous several thousand years has now risen by over 35%.
So whatever the total amounts going in and out “naturally,” humans have clearly upset the balance and significantly altered an important part of the climate system.
3) This warming is detrimental to the Earth's health
I don’t know if there is a meaningful way to define an “optimum” average temperature for planet earth. Surely it is better now for all of us than it was 20,000 years ago when so much land was trapped beneath ice sheets. Perhaps any point between the recent climate and the extreme one we may be heading for, with tropical forests inside the arctic circle, is as good as any other. Maybe it’s even better with no ice caps anywhere.
It doesn’t matter. The critical issue is not what the temperature is, or may be, or will be. The critical issue is how fast it is moving.
Rapid change is the real danger. Human habits and infrastructure are suited to particular weather patterns and sea levels, as are ecosystems and animal behaviors. The rate at which global temperature is rising today is likely unique in the history of our species.
This kind of sudden change is rare even in geological history, though perhaps not unprecedented. So the planet may have been through similar things before — that sounds reassuring, right?
Not so much. Once you look at the impact similar changes had on biodiversity at the time, the existence of historical precedent becomes anything but reassuring. Rapid climate change is the prime suspect in most mass extinction events, including the Great Dying some 250 million years ago, in which 90% of all life went extinct.
What we know about ecosystems, and what geologic history demonstrates, is that dramatic climate changes — up or down or sideways — are a tremendous shock to the biosphere and cause mass extinction events. That, all in all, is not likely to be a good thing.
