The Freakonomics' comment missed the most salient aspect of food production. The substantial but benign increase in CO2 of about 1/3 in the past half century has increased the rate of plant growth (including crops and wild life) about 10% (while, incidentally, requiring ing less water), world wide. At the same time the CO2 has had no discernable effect on global temperatures as measured by exquisitely accurate satellites.

Wasn't it Adam Smith who first note a drop in grain prices when there were more sunspots than normal!

I live in the north, and from the early 1990's till now I have known a dramatic change in our climate, winter is practically gone now. When I was a little boy in the late 1980's we use to have snow from october until march, and it NEVER left the ground. If you think that global warming is not true (like George Bush) you are mistaken, although it is only a minor problem now, within 10 years we will be at a point of no return, you might not have to be around in 20 years, but I will and I am going to take a liberal stand on this issue. So why don't you wake up as well.

Until those who believe humans are causing climate change can explain past climate change when humans either didn't exist or existed in miniscule numbers compared with today, then their fervant belief that "global warming" is caused by burning fossile fuels cannot be taken seriously.

Joe worries about changes since the 1980s. With all due respect, Joe, climate change takes a lot longer than a few decades to become established.

Can "believers" explain what caused the "Little Ice Age"? How about the "Roman Warm Period"? How about the "Medieval Warm Period"?

How many people realize humans have never known Earth's normal climate? How many people know that the planet is locked in an Ice Era that began 60 million years ago? How many know the planet is in an Ice Epoch (a shorter term cold climate lasting upt to a few million years in duration that is embedded within an Ice Era)? Modern humans have existed entirely within an interglacial period of an Ice Age Cycle within an Ice Epoch (all within the Ice Era that began 60 million years ago).

There have only been seven Ice Eras in Earth's history. Can those who promote fear campaigns that humans are responsible for climate change explain what causes either an Ice Epoch or Ice Era to end (or begin)? Do those folks realize that no previous Ice Era has lasted beyond 60 million years (so we're overdue for an end to the current Ice Era)? How many people know that during Earth's typical climate (that has existed for most of the time complex living organisms have existed on the planet) there is no ice at sea level anywhere on the planet (ice only exists at the highest mountain tops during Earth's typical climate)?

A better framework for trying to understand climate change (which, by the way, is perfectly normal) is to know at least something about past climate changes on Earth ... long before humans trod the planet. How else can we determine whether climate change we may be experiencing is normal or abnormal?

Here's a thought ... how about computing the contribution of the explosion of humans and their livestock animals (they all exhale CO2 and consume oxygen) to the change in global CO2 balance? As recently as the 1980s, the world's population of termits produced more CO2 than all the fossile fuel burning put together.

A return to Earth's typical climate can hardly be devastating, considering most life evolved during warm episodes (when we were not locked in an Ice Era).

joe..........i see you mentioned "bush" in your comment. strange how this mess is all "politisized". i finished watching a history channel show on global warming an thought to myself "sure al gore......what do you drive" ,while he was shooting his yoyo off about how bad this all is.if we;re cause'in this mess...how are we gonna stop it......return to simple farming days? i think not!as soon as we get the politicians out of the science.....maybe we can downsize the problem. oh........by the way if bush is ignore'in the problem, clinton in his "great boom" of the economy...only exerbated the problem ! (a better economy= more production....therfore more co2)

So if CO2 is the culprit, how can we reduce CO2? Since cars and industry are only growing worldwide and oil demand, when oil dries up will we be forced to alternative fuel cells. So when that happens, depending on how long the current oil supply goes on (which appears to be new supply and new wells popping up to last another 100 years), what will the CO2 levels be then? Florida and other coastal areas will be under water. That would be pretty cool I know, but why don't we all before that happens, plant a tree, and also develop a machine that sucks CO2 from the atmosphere. That or make a huge straw and suck it out into space. That way we can regulate the CO2, therefore the temperatureof the planet. I live in the Pacific NW, so before you do, make the average temperature 70F here in winter before you plug it in please.

Folks,
There is another player in all this global warming issue that wasn't discovered until about 4 to 5 years ago. That player is the fact that the Van-Allen Belts are shrinking. What's this got to do with global warming? They sheild us from the sun's magnetic energy and solar winds. This means more of the sun's energy gets to the surface of the earth. So it gets warmer. Why this is happening? It is believed to be a precursor (sp) to a magnetic pole shift. This has happened nine times before and we are 350 million years overdue according to the experts. When it's over the Van-Allen Belts will return to their normal strength and we'll get colder?? Don't know about that but I would consider it possible. Program was on NOVA (PBS) a month or so ago.

IT REALLY DOES NOT MATTER, AS FAR AS GLOBAL WARMING IS CONCERNED. BUT IT DOES MATTER WHEN ALL OF THE INDUSTRIES JUST KEEP ON ALLOWING POLLUTION FROM AUTO,S , TRUCKS, TRAINS, AIRLINERS, SHIPS AND ANYTHING YOU CAN POSSIBLY THINK OF IN TERMS OF POLLUTION DOES IN FACT CREATE MORE AND MORE DISEASE. SMOKING, CARBON DIOXIDE, SECOND HAND SMOKE ETC... YOU SURELY GET THE PICTURE.ALL THESE THINGS ADD UP TO " NO GOOD FOR HUMAN BEINGS, NATURE, OR ANY LIVING ORGANISM".
WE ALL CAN TRY TO CONTROL OF OUR OWN PERSONAL BEHAVIOR. NOT ALLOW OTHERS, POWERFUL OR POOR, WE ALL LIVE ON THIS ONE PLANET.AND UNTIL ALL OF US FIND ANOTHER TO LIVE ON WE SHOULD AT THE LEAST RESPECT WHAT WE ALL HAVE. AND THAT IS OUR PRECIOUS LIVES. MAY YOUR OWN HIGHER POWER BLESS AND PROTECT ALL OF US. THANK YOU FOR TAKING THE TIME TO READ MY THOUGHTS ON GLOBAL WARMING AND THIS PLANET WE ALL CALL HOME.

I've read many, many things on global warming. The results predicted are inevitably catastrophic. People will die from the heat, droughts will increase, plants and animals will die, etc. etc. Why is it that there is nothing good that might happen? Perhaps fewer will freeze to death, perhaps less fuels will be needed, perhaps some plants will thrive, perhaps more rain will fall in places that need it (and not just hurricanes, tornados and floods). There seems to be no rational discussion, but just predictions of catastrophes apparently designed to get people to beleive the prediction that global warming is occurring out of fear.

Has anyone considered it might be good? And that at some point it might reverse anyway, regardless of what Al Gore does?

Global Warming? I Live in the state of Indiana, and it's currently April the 5th. We have 3 Degree temperatures outside(3:00PM), we are under a freeze warning for today, and a freeze watch for the next several days. The normal temperature for us (emphasis on normal) is in the 50's to 60's. It is to remain cold like this for the rest of the month. DON'T talk to me about Global Warming...please.

Joe cool,

co2 acts like insulation, (Think about loft insulation or how a fridge keeps cool, blanket ,coats and co2 do the same thing) if its cold where you are the insulation of co2 will keep it cold until warm air heats it up. Cold air is being swept in with the jet stream; you are having a late winter storm like most of Europe. So Stop thinking warming and start thinking climate change.
The misunderstanding about AGW is due to ignorance about climate time lines. This warming period started 12000 years ago, 8000 years ago humans began chopping down trees and we started farming. This practice caught on and industrialized farming was mechanized shortly after the industrial revolution when farming also became globalized. Bringing us to today when 2/3rds of forest have disappeared and 40% of fossil fuel have already been incinerated.
OK? Even the sea is getting so warm that it cannot absorb co2. The ocean is becoming acidic which is dissolving limestone coasts, right now, sending a positive feed back of co2 from nature itself!, tipping point has begun as the oceans, permafrost , forest dieback and deforestation release more co2 in a week than industry can in a whole year.
But if you ask what caused the last Ice age when humans were not industralized, 75000 years ago I would say volcanic activity and possibly tree dieback was enough during a 170 000 year global warming period.
Do you see the time line? Hummans had 170 000 years of pleasent climate, we managed 12, Can you understand how human activity has change the natural cycle; which has hastened climate change? We have managed to add enough co2 into the mix in 200 years and before the show began we stripped the planet of forest so that natural and man made co2 has nowhere left to go, so we are screwed. We cannot plant enough trees and carry on farming now they want to plant fuel crops. We cannot win this one, can we?
Oh and it is political, because democracy cannot function without the wealth created from fossil fuels while millions in population survive today only because consumerism allows enough wealth to keep them comfortable. However it cannot go on forever and the good times have nearly ended.
My advice is to carry on as usual, as the alternative is to pretend there is something that can be done. Alternative energy can only provide more energy, unless the plan is to stop the finding and mining of fossil fuel but as I don�t see anyone promising to ration its use, they must be planning business as usual while they tax you in an effort to become carbon nuetral or some such feel good claptrap.