Basically, the CO2 concentration has grown from a low of 180 ppm to today's concentration of 380ppm. The chart covers from 1958 to today. In the past 400,000 years, the concentration in the atmosphere has never exceeded 280 ppm - until 1950, when it surpassed the 280 ppm mark. The chart goes to 2004; the ppm today is > 385 ppm.
What does this mean for global temperature? How about this (thru 2006); the source, very long, article is here.
The picture below should tell you something. The summer melt in Greenland has grown by the shaded amount in just 10 years. 10 freakin' years.
How about other ice indicators around the world? Back in 2002, the alarm about glacier melting was already being sounded, as in this article from The National Geographic. Here's just one quote from the article:
Here's a before and after picture of a glacier in Montana (sourced here)
Most of Earth's 160,000 glaciers have been slowly shrinking and thinning for more than a century as the climate warms up from both natural causes and human activity.
But scientists say the melt rate has accelerated dramatically since the mid-1990s, which was the hottest decade in a thousand years, according to data from ancient ice cores and tree rings.
A glacier in the Peruvian Andes, Qori Kalis, is losing as much ice in one week as it used to surrender in a year, according to Lonnie Thompson, a geologist at the Byrd Polar Research Center at Ohio State University in Columbus.
We know that the melting rate today is much larger than it was in 2002. Back in 2002, scientists thought that the Arctic might be free of ice during the summer by 2100; now, they think it will happen by 2030. Even just 9 months ago, the date was put at 2040 or later; in just 9 months, they've moved the date up by 10 years.
Something that's not talked about, outside of scientific communities, is that the RATE of CO2/methane increase in the atmosphere is increasing at about .3 ppm per year. So, in 3 years, the RATE of Co2 increase goes up about 1 percent; right now, the rate of increase is about 2.6 ppm/year.
Take a look at the amount of CO2 projected to be released in the future - and this graph is now out of date, since it didn't properly take into account the growth that would hit China and India.
The point is: we're screwed. 30 years ago, it was already too late not to get where we are - and we're still not doing anything, meaningful, about it. We're also not preparing people to move away from the coasts, and we face a 16 foot rise by 2030-2040. That doesn't mean that, in the last 10 minutes of 2030, the sea-level will come up 16 feet. In my lifetime, the world is going to change dramatically; warming, sea level rise, increased strength of storms, energy shortages, food riots, drought, floods, etc. etc. etc. etc.
Obviously, some Chinese guy has cursed the world with the old curse of:
May you live in interesting times.
Our times are WAY too interesting for my taste.
Have a nice day!