SIngular why do you editorialize when you ask a question...?
Building a high-resolution picture of how temperatures have changed is no mean feat. Thermometre readings only go back to around 1860, so we have to use proxies to delve further back. Tree rings, for instance, are thicker during warm years when trees can grow faster.
Shaun Marcott of Oregon State University in Corvallis and colleagues used 73 proxies to reconstruct temperatures throughout the Holocene – the epoch that began 11,300 years ago, after the last ice age. Their analysis shows that over thousands of years, temperatures rose and fell by less than 1 °C. "It took 8000 years to go from warm to cold," says Marcott. Agriculture, communal life and societies with various forms of government all arose during this relatively stable period.
larger article
http://www.newscientist.com/article...hockey-stick-graph-revealed.html#.U2w5rV5mv3w
There are hundreds of approaches to track the climate globally...they all say the same things....
The graph above is the result of the multiple proxies used to extend back 11k bp to the last ice age.
The confirmation is the change over time matches the change to be expected as the earth moves to a cooler regime due to changes in it's orbit known as Milankovitch cycles.
Then industrial civilization comes along.
Coal and oil and gas are burned, increasing the C02 in the atmosphere to levels not seen for millions of years.
CO2 traps IR so more warmth is retained....this is radiative imbalance - we are keeping more than we radiate out.
So the earths geophysical systems, air, ice, water retains more heat as it cannot radiate it out as fast.
The huge gain is in the ocean....the air is somewhat minor in comparison.
It's getting warmer...
CO2 traps IR. It will not reach a new equilibrium for a while and it will be at a temperature not seen for millions of years.
IF we could hold it at 2C rise over the 20th century average then we would just barely stay within the Holocene Optimum some 8,000 years ago.
I do not think we will, and we need to prepare for the consequences. Already only .8C into the climb the consequences are severe for some ...and the changes in the Arctic astonishing.
There is far far more to come and we continue to add CO2 which unfortunately stays with us for 1000s of years.
We're responsible for this.....first world civilization built its wealth on fossil fuels. Now we have to cope with the consequences of that wealth building....party is over ....the bill is due.
One of the early consequences of AGW is extreme weather. and the annual bills for that are getting to be astronomical. Just one state...
California drought could drain $8 billion, spike food prices
www.cnbc.com/id/101514409
Mar 21, 2014 - California, hammered by a severe drought, may see nearly a million acres of idle land this year because of a lack of water, a report said on ...
Welcome to the Holocene.