According to the IPCC 4th Assessment Report (2007):
- Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level.
- At continental, regional, and ocean basin scales, numerous long-term changes in climate have been observed. These include changes in Arctic temperatures and ice, widespread changes in precipitation amounts, ocean salinity, wind patterns and aspects of extreme weather including droughts, heavy precipitation, heat waves and the intensity of tropical cyclones.
- Paleoclimate information supports the interpretation that the warmth of the last half century is unusual in at least the previous 1300 years. The last time the polar regions were significantly warmer than present for an extended period (about 125,000 years ago), reductions in polar ice volume led to 4 to 6 metres of sea level rise.
- Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations. This is an advance since the [Third Assessment Report’s 2001] conclusion that “most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations”. Discernible human influences now extend to other aspects of climate, including ocean warming, continental-average temperatures, temperature extremes and wind patterns.
Let us take a look at some of the evidence:
This post is by guest Blogger Scott A. Mandia, Professor of Physical Sciences at Suffolk County Community College, Long Island, NY. Mandia holds an M.S. Meteorology from Penn State University and a B.S. Meteorology from University of Lowell (now called UMass – Lowell). Mandia has been teaching introductory meteorology and paleoclimatology courses for 23 years.
20 of the warmest years on record have occurred in the past 25 years. The warmest year globally was 2005 with the years 2009, 2007, 2006, 2003, 2002, and 1998 all tied for 2nd within statistical certainty. (Hansen et al., 2010) The warmest decade has been the 2000s, and each of the past three decades has been warmer than the decade before and each set records at their end. The odds of this being a natural occurrence are estimated to be one in a billion! (Schmidt and Wolfe, 2009)
There is more data here demonstrating just a part of the huge amount dealing with the increasing temperatures of our globe and the effects this has on a range of terrestrial processes.
People can try and deny parts but even this small portion makes it lunacy to deny all of it. So let’s just admit that climate change is happening.
This will have huge economic effects, no matter what we do. So why not try and do things that might actually help and plan for things that will be beneficial. Aren’t we the species that controls its environment?
No matter whether someone denies AGW or not, we should be doing things the ameliorate the effects of climate change. And soon.