This will probably turn into a GD issue, but I want to know what most scientists think about global warming. Is it happening? Is it man-made? Are doubts about it just wishful thinking or is it really still open to debate?
Thanks for your help,
Rob
The majority – but not quite consensus – opinion in the scientific community is “yes” to both.
Here’s a good place to read up on it: http://en.wikipedia.org/wiki/Global_warming_controversy
There aren’t more than a very few reputable scientists still expressing doubts that we’re currently experiencing a global warming trend - at least none that can be taken seriously. There is, however, still reasonable debate over the cause (or more likely - causes) of it. As there is over the magnitude and prognosis.
I would say, based on my own experiece, there is a very strong consensus among scientists - certainly, among those I know personally, and from what I have heard in conferences - that not only is global change occurring but that the major cause is human activity, in particular burning of fossil fuels.
Public statements by scientists are actually much more careful and conservative on the issue than what I have heard expressed personally or in discussion in conferences.
It does risk hitting GD territory. But basically yes.
On 7 June 2005 by the national science academies of Britain, France, Russia, Germany, US, Japan, Italy, Canada, Brazil, China and India issued the following statement:
There will always be uncertainty in understanding a system
as complex as the world’s climate. However there is now
strong evidence that significant global warming is
occurring. The evidence comes from direct measurements
of rising surface air temperatures and subsurface ocean
temperatures and from phenomena such as increases in
average global sea levels, retreating glaciers, and changes
to many physical and biological systems. It is likely that
most of the warming in recent decades can be attributed
to human activities. This warming has already
led to changes in the Earth’s climate.
The existence of greenhouse gases in the atmosphere is
vital to life on Earth – in their absence average
temperatures would be about 30 centigrade degrees lower
than they are today. But human activities are now causing
atmospheric concentrations of greenhouse gases –
including carbon dioxide, methane, tropospheric ozone,
and nitrous oxide – to rise well above pre-industrial levels.
Carbon dioxide levels have increased from 280 ppm in
1750 to over 375 ppm today – higher than any previous
levels that can be reliably measured (i.e. in the last 420,000
years). Increasing greenhouse gases are causing
temperatures to rise; the Earth’s surface warmed by
approximately 0.6 centigrade degrees over the twentieth
century. The Intergovernmental Panel on Climate Change
(IPCC) projected that the average global surface
temperatures will continue to increase to between 1.4
centigrade degrees and 5.8 centigrade degrees above 1990
levels, by 2100.
Yeah? Interesting. Thanks for the inside peek.
Not global, I know, but the CET (Central England Temperature series) graphs at the Hadley Centre website make uncomfortable viewing: http://www.metoffice.com/research/hadleycentre/obsdata/cet.html
In fcat they also have global temperature charts - http://www.metoffice.com/research/hadleycentre/CR_data/Annual/HadCRUG.gif
It seems fairly cut and dried that global warming is happening. The debate nowadays seems mostly focused on weather it’s man-made, and when you consider that CO[sub]2[/sub] levels are currently at their highest for at least a million years, it’s not hard to see why many scientists are convinced.