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After the Wisconsin glacier retreated from the Chicago region, it still occupied and dammed the northern end of the Lake Michigan basin, forming glacial Lake Chicago.
This lake, which covered most of present-day Chicago, was higher than modern Lake Michigan.[By analyzing pollen and fossilized vegetation in this ancient Ice Age lakebed scientists have determined that at the closing of the last Ice Age, the southwestern Chicago region and the northern half of Illinois was like no other place on earth: covered the landscape.
The world pumped 39.8 billion tons (36.1 billion metric tons) of carbon dioxide into the air last year by burning coal, oil and gas.
That is 778 million tons (706 metric tons) or 2.3 per cent more than the previous year, despite increasingly urgent warnings over the need to curb greenhouse gases Experts said at current rates the 'quota' for the total amount of carbon dioxide that can be released into the atmosphere without pushing the world beyond 2°C of warming could be used up within 30 years.
This spruce forest lasted for about 1,000 years, until about 15,000 years ago, when climate warmed and deciduous trees became more abundant, including balsam poplar (Populus balsamifera), black ash (Fraxinus nigra), and ironwood (Ostrya virginiana or Carpinus caroliniana).
Balsam fir (Abies balsamea) also was present, as was spruce, although not as abundantly as before.
Although the glaciers had retreated, the climate was still quite cold.
About 16,000 years ago, the spruce forest became denser, and closed forest developed.
The exact date humans came to North America will not be found soon, but the Hebior and Schaefer Wisconsin mammoth sites about 350 miles northeast of our recovery site were recently carbon-dated to 15,000 to 16,500 years ago and contained artifacts that were basically cutting and skinning tools.
The UK and Luxemburghave the worst average carbon footprints, while Romania, Hungary and Bulgaria are the greenest countries.
The map suggests that income is one of the most important drivers for a region's carbon footprint, with the wealthiest countries the least green.
In order to keep temperatures from rising by more than 2°C above pre-industrial levels, beyond which the worst impacts of climate change will be felt, more than half the world's fossil fuel reserves may need to be left in the ground, they said.
Emissions, which are primarily caused by burning fossil fuels, will have to decline by more than 5 per cent a year to give the world a 50/50 chance of keeping temperature rises below the 2°C threshold.
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This question has been hotly debated for over a century, especially now with the recent interest in the last Ice Age.