Nightly News | September 27, 2013
>>> now to the big headline from climate scientists tonight. the u.n. international panel on climate change says we are hurtling toward the day when climate change could be irreversible with catastrophic consequences, they say. this group is now 95% sure that humans are responsible, and it's only going to get worse if we don't take drastic measures.
>>> our report tonight from our chief environmental affairs correspondent anne thompson .
>> reporter: we're warming our world by burning coal, oil and fossil fuels. today the world's leading climate scientists warn it will get worse, with fewer very cold days and more hot ones. heat waves will be more grent and last longer. rising sea levels already altering this nation's coast and making storms like sandy more destructive could go up nearly three feet by the end of the century swamping parts of new jersey and dramatically changing florida's coast. and glaciers, a key source of drinking water for parts of the world are losing ice everywhere but new zealand.
>> we've seen an increasing number of regions over the decades starting to lose ice, but this is the first time we've seen it almost globally.
>> reporter: most ominously, the report says we are in real danger of exceeding our carbon limit of 1 trillion tons. scientists say that would warm the earth more than 3 1/2 degrees fahrenheit making the impact much more dangerous. how much longer can we go?
>> the rate of emission has been accelerating. at this rate we've got 30 or 40 years before we have to completely stop and go to zero.
>> reporter: there are ways to slow the damage. increasing energy efficiency , usy renewable such as solar and wind and setting limits on carbon pollution can all lower emissions. but if we persist, scientists say the real challenge will be taking the global warming gases out of the atmosphere and no one has come up with a workable solution for that yet. anne thompson , nbc news, new