So many educated people I know here if California are totally clueless about environmental issues and global warning.

This is truly a shame and I believe it will take a generation to rectify it as elementary students are educated about this issue in their schools.

Of course, if we in the US keep electing knucleheads like George W Bush, the cover up on environmental issues will continue.

Unlike the Country and Western song; "I'm proud to be an American" I am ashamed of it given that we in the US are only about 5% of the worlds population yet produce about 40% of the carbon.

Ron Vanderford Burbank, California US

Ron Vanderford, Burbank, California, USA

To my knowledge the States and China are to top too polluters. It is a shame that Americans are barely finding about this and continue to do nothing. Some like Gary from Seattle still fail to believe.

I am embarrassed of my country for its actions in the past decade. I am want to change things for the better. America is simply using too much. I am scared of the dire consequences we, as human beings, may face. I am not even the age of vote yet, but I plan to make changes for the better and try to fix what is broken in the white house.

My heart goes out to Bangladeshi families affected by the cyclone.

Joshus Smith, Compton, CA, US

Go to S America where the CO sink is and try to filter the air.
That's where it's spreading all over.
There is a lot of water 1000 miles down, somewhere in China. Maybe we can pluck it up, to keep salt water from mixing with it, or bring it up.

Armando Garcia Perry, Uvalde, Texas

I'm glad to see that climatic change has finally been accepted as real by mainstream American media. I received my bachelor's degree in a major that covered environmental issues in the 80's.

It's sad to see that it has taken so long for these issues to be known on a major scale. So much information has been covered up or dismissed as "junk science " by the Bush administration.

There are so many interconnected issues to write about. But the main thing is to educate yourself. You can start with Rachel Carson's "Silent Spring" (1960) and follow it up with Frances Moore Lappe's books. Carson touches on the effects of toxins we dump in the environment and Lappe's delves into the politics of food.

FYI - California currently is in a drought ( 5th year ) but no conservation is occurring. There is some talk of conserving what water remains starting next year. In the meantime, more houses are approved to be built on Central Valley farmland, flood zones and the fire zones of SoCal

Aurora Sarabia, Berkeley, USA / California

The U.S., England, Germany, etc have been polluting the air for decades as they industrialized. Now China wants to industrialize like those countries and is being blamed for not doing enough to stop global warming. Wow, guess it is their bad luck they didn't industrialize like the other nations back in the 18th century. As far as I'm concerned, the earth is getting warmer, but I do not believe humans are behind it so I'm not supporting any government regulations forcing our corporations to cutback emissions or forcing us to cut back on our driving. If a corporation or person wants to do it voluntarily, that's fine with me. But keep government out of it.

Gary, Seattle, USA

Yes, there may be early snow fall in many parts of the world. That is why this global crisis is more correctly called "Global Climate Change." The term "Global Warming" is misleading.
Most scientists now urge humans to realize that its all about Climate Change, which means massive disruptions in temperatures will take place, and some places on our planet will experience very cold, early winters, while other places will have terrible droughts. This Grand Experiment, perpetrated by humans, will also mean more flooding, forest fires, less fresh water, and species' extinctions. We humans are insane.

Rosemary Lowe,RN, Santa Fe, U.S. /New Mexico

The scientific evidence is pretty clear, and continuing to grow. For those confused by conflicting websites, I recommend John Houghton's "Global Warming: The Complete Briefing", which is a 360-degree view of the situation starting from the scientific basics. Houghton is a former chair of the IPCC technical committee, Cambridge professor of climate studies, expert in atmospheric physics, etc.

To respond to someone's concern for the broad range of temperatures: Nearly all of the uncertainty is due to the question of what the humans will do to control their emissions. You get the low number if they do a lot, you get the high number for "business as usual". The uncertainty introduced by the modeling of the physics itself is a rather small percent.

Neal J. King, Munich, GERMANY

It is not so much who you believe or don't believe, or what you believe. Only an idiot would choose to deny what is obvious to most of the world. The climate is changing and it literally scares the hell out of me. We haven't had a decent spring rain in years where I live and now the summers get hotter and drier as well. Without water life will cease to exist. Go ahead, pretend you don't see it, blame someone else but the bottom line is that everyone is responsible and EVERYONE needs to step up to the plate and take responsibility. If what is happening doesn't scare you or at least rattle your cage then just keep watching because unless changes start being made at the higher levels we are all in for a situation that may be too late to do anything about then. Ever watch "The Day After?" I did, and it bothered me that we are headed in that direction. If the changing weather patterns don't make us stop and think then NOTHING will.

Buddy Garriott, Fulton, Missouri

Isn't it remarkable that on the same frontpage of todays Times is a link to an arcticle about massive early snow fall in the Alpes? Don't tell me this is a one-off, because in northern Spain (and other places), the first snow this year fell at the end of August. Could we be witnessing, perhaps, the beginning of a period of global cooling? Could it be that the IPCC's leading scientists are somewhat overestimating their level of expertise?

Ed Zuiderwijk, Cambridge, UK

Climate Change Deniers take note. This is the real science, from the real scientists. Yes, there is disagreement about how much will happen and how fast, but every scientist bar a tiny minority of mavericks agrees that climate change is a serious problem and almost certainly our fault. The reason the mavericks get ignored is that they have consistently failed to produce evidence to back their views, which is also why some of them have taken to throwing deceptive half-truths at the public instead.
This is a wake-up call not just to governments but also to those individuals whose solution to climate change is to pretend there's nothing to worry about. Every one of us can act to minimise our footprint without a drastic change in lifestyle.

Dr Richard Milne, Edinburgh,

Like any sensible reader would believe anything that comes
from the UN? I don't think so.
Read: One world global government, social justice,
wealth transfer to the third world, and at last control over
everything and everybody.
A wicked institution, only worthy of being dismantled.

Dave M., london, USA / UK

Climate change is not the problem; it's going to happen no matter what we do. The problem lies with mankind not adapting to changing weather systems. Higher \ lower temperatures are not a problem if you prepare for them well in advance.

Ben, Wilmslow, Cheshire

It is strange that we hear just the opposite from other scientist. Man has contributed to the very very small climate change, however I feel, based on the research of many scientist, that the change is part of a cyclical pattern. The temperatures of the oceans have varied over the past hundreds of thousands of years. The world has been a ball of ice, a virtual hell of heat and after things finally settled down the temperatures have varied enough for the Vikings to settle in Greenland in the 15th century but were forced to leave after a hundred or so years due to the freezing temperatures. The slight increase that is forecast for the next fifty years is nothing compared to the extreme changes in the past. Yes man is contributing but are they also contributing to the temperature rises on Mercury, Mars, and Venus? If so, we need to do something about that also.

Bert Lasagna, Charlotte, , NC, USA

For those of you who don't think the climate is changing along with weather patterns its time to get your head out of the sand. We are the cause and right now China is firing up one coal plant after another...what have they got to say out their contribution to the problem? We should have been going green 30 years ago!!

We need to do and take action now!

illustrator5, anytown, USA

We have increased CO2 content of an entire planet 30 percent and destroyedmuch of the virgin forests on the same planet. Evidence like melting ice shelves, disappearing glaciers, record breaking hurricane seasons, shortened cold seasons, heat waves, forest fires, drought, and deluges, by themselves don't mean much, but collectively, they are getting hard to ignore. The weather is changing.

Jo-Ann, Mesa, Arizona

It will happen faster than anyone imagines.
just like rolling a snowball and that is happening now compared to the models that science is using. next year the models will reflect quicker than expected change.
murphy's law...what ever can happen will.
I'm just glad to be alive to see it.

tom sydor, detroit, michigan, oakland

Climate scientists used to be low paid people who never got invited to parties; now they are very well paid people with large grants and contracts, who are among the most popular people at a party. Please explain how this is not a strong motivator to continue portraying global warming as both critical, and human caused (and therefore something we need to do something about).

Michael, Boulder, CO

I find fault with the headline you have chosen. There is a big difference in "will" and "could". The headline is very missleading. The quotes in the body of the article only indicate that there "could" be bad consequenses. Or is something being left out of the quote?

Morton, San Diego, CA

I saw a report on Discovery Channel that demonstrated sea level increase could be dramatically more severe. It said that for every foot or so of sea level increase the affect on coastline reduction would be YARDS, not inches. In LA, for instance, the affect would be 700-800 feet of coastline submerged. The affect across the entire globe would be significant.

The problem is that models used for such predictions are imperfect at best.

This report sounds suspiciously soft, like the "best case scenario" from the spectrum of all possible outcomes. Is the UN panel afraid of being labeled "alarmist?" Who is making the decisions about what goes into the report, and what doesn't... And more importantly WHY?

JC Weatherby, Los Angeles, California

Temps rising between 1.1 c and 6.4 c? Well thats a pretty big window, which suggests to me these so-called experts are almost as much in the dark about it as the rest of us.

greg, San Francisco, USA

I think it's a power play by the UN to stay relevant.

Jer Cooper, Yuba City, CA

The IPCC consists of a rotating body of thousands of leading scientists from around the world from an array of disciplines. If there was any credible scientific evidence to the contrary, it would be reported. But you'll have to read more than 3 words of the report to find out if there is.

Jason Deardorff, Denver, CO

A new study revealed that the massive global extinction that you're referring Caleb Jones was also caused by Volcanic eruption. Either way, it looks like it's time for humans to evolve or be extinct.

Alexander Davis, Berkeley, USA/California

Sounds like the Zionists who 'create irreversible facts on the ground'

Raj, CALGARY AB, CANDADA

I simply dont believe The IPCC report. Average global temperatures have not changed in the last 10 years.
The greatly increased world population is the main problem which has let to accelerated deforestation, land erosion and accelerating industrial pollution.
IN 10 YEARS TIME WE WILL BE WONDERING WHAT THIS WAS ALL ABOUT; EXCEPT THAT WE WILL STILL HAVE ALL THE PROBLEMS ASSOCIATED WITH INCREASING WORLD POPULATION.

J GALLAGHER, London, UK

'abrupt and irreversible'?

I can agree with abrupt, but come-on, 'irreversible'? It's rather anthropocentric of us to believe that we have the capability to 'irreversibly' alter our planet. I think we don't give our planet enough credit for its ability to adapt to climate changes it has faced in the past. At one point there was massive global extinction (likely due to comet strike) and the earth has recovered from that.

'Irreversible'? No. 'Devastating to mankind and current ecosystem?' Yes.

Caleb Jones, Seattle, Washington,

Of course we'll never see anything on "some of the world's most eminent scientists" who disagree with these findings.

John, Colorado Springs, USA/Colorado

if the subjec isnt about population overshoot not worth talking about. whats the chances? not until the last tree! situation hopeless.!

winston smith, kismet, ny, 11706

The polar bears look like they are doing fine, and are 4X their 1950 population. Antarctica just set an all time record for maximum sea ice. Total sea ice on the earth is about average right now. There is no evidence of increased hurricane frequency or intensity. Check the facts for yourself.

This is all a bunch of mass insanity.

Patrick Henry, Bristol,

They are STILL preaching this baloney?!

I"m still waiting for the Ice Age predicted by scientists in the 70's to arrive.

Scott, Durham, NC, USA

The true, and fundamental, cause of not only Global Warming, but stress, crime, drugs, homosexuality, suicide and all of Satan’s other gifts, is overpopulation. If the globe's human population were only 10 million, we could all be driving mehtane-powered SUV transformer-bots and flushing mercury down our toilets a million times a day, and the ecology wouldn't even have a dent in it. Let's start by telling the truth.

eugene, heidelberg, germany

The true, and fundamental, cause of GB is overpopulation. If the globe's human population were only 10 million, they could all be driving SUV transformer-bots and flushing their toilets a million times a day, and the ecology wouldn't even have a dent in it. Let's start by telling the truth.

eugene, heidelberg, germany

Will this really do any good? It has been known for years that we are in a disasterous situation and need to act NOW! But we need another report, another summit, another agreement to maybe reduce emissions after 2012.
If the temperature rises by 6.4 C we will lose most of our forna and flora. If it rises just 1.1 C, this is still disasterous and we will lose many species of plant (and the wild life dependent on them) as for example tree species can not migrate to more suitable climates quickly enough.
This should be the worlds No.1 priority but the major culprits like the Sates are far too interested in maintaining their dominant wealth and thefore military advantage to protect themselves from the religious meneace of today.
Let's get rid of religion so we can concentrate on saving the planet!
Stop arguing over whose god is right, cos none of you will be saved if this continues.

Rosbif, Antibes, France