Coloured lines; various computation methods. Black lines; modern measures.
Has the current warming of the earth a natural cause? It now appears that the average world temperature has risen faster in the last 150 years than ever (see also my earlier blog).
Even if we look back to the days of the Roman Empire, we do not find an event that is somewhat comparable to the warming of the past decades This is an important indication that current warming has no natural cause. These are the conclusions from three studies
on historical climate changes published this week in Nature and Nature Geoscience by international research groups led by researchers from the University of Bern.
The graphic representation that wraps up the major
results is a kind of hockey stick, with a sharp bend up at the end: the moment, halfway through the last century, when the man-fired greenhouse gasses began to affect the atmosphere, and resonate in the climate. Surprisingly and disturbingly, the warming of
the last 150 years is happening all over the earth's surface: for the first time, it is getting warmer everywhere. The argument often used by climate skeptics that climate "just always changes" loses meaning concludes the group