Global
warming trend over the last 200 years or so is a scientific fact, (scientist are able to bring out the raw data as back up).
What his paper actually proves is once you remove any long term
warming trend from the temperature record, it leaves little room for any warming.
So, I was wondering what the thinking was about thresholds with respect to the
current warming trend on this blog.
However, something does seem to have happened to slow the global
warming trend for that period, when compared to the runaway warming of the 1980s and 1990s.
According to last month's paper, it makes more sense to compare
recent warming trends with the 30 - year period from 1972 - 2001, when temperatures rose more rapidly.
Climate models show an increasing
warming trend with altitude, but balloon data shows a slight cooling with altitude in the tropics.
Using higher resolution temperature data supplemented with updated satellite measurements, Screen 2010 analyse the
observe warming trend in each season.
So why is it necessary to explain the abrupt
warming trend at the end of the 20th century any differently?
Yes, the oceans are warming but these trends are 10 % to 20 % of the predicted
surface warming trend of about 0.2 C per decade.
It is interesting that the eastern pole sometimes cools among the
strong warming trend over this region.
Nearly half of the 20th
century warming trend occurred from 1910 to 1945, but CO2 emissions didn't increase enough to explain most of the warming.
Such adjustments seem to overwhelmingly show a massive
warming trend not present in the raw data.
Human fossil fuel use is also behind a
general warming trend in the oceans observed over the past 50 years that increases the resistance to CO2 uptake.
Temperature monitoring stations exist around the globe, on both land and sea, and we see a
clear warming trend from many locations.
The authors also assume that the linear man - made
warming trend which they've thrown into their model will continue at the same linear rate into the future.
So we should never allow ourselves to lose sight of the catastrophe we face if
present warming trends continue.
But that's not what we are seeing, we are observing a highly significant, very
rapid warming trend.
The climate in most places has undergone minor changes over the past 200 years, and the land - based surface temperature record of the past 100 years
exhibits warming trends in many places.
This means that when modern global
warming trend began in the 1970's, the correlation between sun and climate broke down.
This graph shows that since the recent global
warming trend started around 1975 the sun has NOT been heating up.
But the expected
slow warming trend that results is unlikely to lead to rapid climate change.
For every cooling trend a much
higher warming trend exists to more than compensate the cooling so as to keep the mean trend warming.