Dr. James Hansen at NASA proposes 350 ppm as a safe level to stabilize the climate, halt sea level rise, stop glacial melt, and make the weather like it used to be in the good old days. Others have suggested that we have to cut CO2 back to 300 ppm.
There is no need to speculate about what would happen at 300 ppm, as we have plenty of historical records from the 19th century – when CO2 was below 300 ppm.
The glacier at Glacier Bay, Alaska retreated an incredible eight feet per day during the 19th century. It is quite clear that dropping CO2 below 300 ppm will not stop glaciers from retreating.
http://soundwaves.usgs.gov/2001/07/glacierbaymap.gif
Now let’s focus on a small sampling of some of the more notable weather events during the years 1886 – 1894.
1886 was the most active hurricane season in US history. Seven hurricanes made landfall, including two major hurricanes.
Highest Saffir- Central Max. Name and Category by Simpson U.S. Pressure Winds States Category 1886 Jun TX, N2; LA, 2 2 973 85 ----- 1886 Jun FL, NW2; I-GA, 1 2 973 85 ----- 1886 Jun FL, NW2; I-GA, 1 2 973 85 ----- 1886 Jul FL, NW1 1 985 70 ----- 1886 Aug TX, C4 4 925 135 "Indianola" 1886 Sep # TX, S1, C1 1 973 80 ----- 1886 Oct LA, 3; TX, N2 3 955 105 -----
http://www.aoml.noaa.gov/hrd/hurdat/ushurrlist18512009.txt
Terribly destructive storms also struck Europe that year.
1887 was a year of terrible floods and droughts – nearly a million people drowned in China, and Australia suffered one their worst floods on record – while England suffered an extreme drought.
http://news.google.com/newspapers
1888 saw more severe floods in China, Chile and Australia, and a massive snowstorm on the east coast of the US.
http://news.google.com/newspapers
1889 saw more catastrophic flooding in China, terrible forest fires in the US, and a disastrous drought in Russia.
1890 saw Brisbane under 10 feet of flood water and massive forest fires in the Rocky Mountains
http://news.google.com/newspapers
1892 saw horrific flooding in China, terrible heat and drought in Australia, heat and drought in Europe, a massive typhoon in Japan, crippling heat in the US, and terrible tornadoes.
http://trove.nla.gov.au/ndp/del/article/8445064?
1893 saw record heat in Australia
1894 saw massive forest fires in the US and record flooding in Queensland.
http://trove.nla.gov.au/ndp/del/article/3587788?
There is abundant evidence that Hansen’s idea of a stable climate comes from a spectacular lack of historical knowledge about past climate. The climate never was and never will be stable.