JUDY WOODRUFF: Now we move on to the aftermath of last week's summit on climate change in Copenhagen.
Yesterday, in his White House interview with Jim Lehrer, President Obama acknowledged that he didn't believe the summit had been a complete success.
U.S. PRESIDENT BARACK OBAMA: People are justified in being disappointed about the outcome in Copenhagen. What I said was essentially that rather than see a complete collapse in Copenhagen, in which nothing at all got done and would have been a huge backward step, at least we kind of held ground and there wasn't too much backsliding from where we were. It didn't move us the way we need to.
JUDY WOODRUFF: Tonight, Ray Suarez, who covered the Copenhagen summit for the "NewsHour," reports on one of the implications of deferring decisions on global warming: the possible effect on global public health.
RAY SUAREZ: There may still be some debate over what's causing climate change, but, amid all the back-and-forth in Copenhagen over economics and development, there was no debate about the fact that something's up, and that it's changing lives.
The World Health Organization used the climate conference to press the point that a warmer planet will be a sicker one, and a less polluted planet saves lives.
DR. DIARMID CAMPBELL-LENDRUM, World Health Organization: From the public health point of view, we already deal with massive impacts on -- on human health of climate-sensitive diseases -- 2.2 million people die every year from diarrheal disease. It's highly sensitive to climate -- 1.1 million die from ... disease. That's highly sensitive to climate -- 3.5 million die from undernutrition. That's entirely dependent on agricultural production.
And all of those deaths occur in the parts of the world that are going to be most affected by climate change. So, this, for us, is more than an environmental issue. It's more than a debate about targets or about how much it is going to cost. It is -- it's a debate about basically saving people's lives.
RAY SUAREZ: Diarrheal diseases, malnutrition, those are poor people's diseases. And the WHO insists the health effects of climate change are not just a poor person's problem.
DR. MARIA NEIRA, World Health Organization: Americans will benefit a lot if you embark on a campaign to reduce carbon emissions. They will reduce cardiovascular diseases in a very important way. They will probably create places at the level where you can have a more -- a less sedentary lifestyle.
People can walk or eventually even go by cycle. And therefore, you will fight obesity, which is one of the major public health problems that we are having at the moment.
RAY SUAREZ: But most climate scientists say we're still in the early stages of global climate change, and, for now, the most severe effects of rising sea levels or too little rain followed by too much is among the developing world's major concerns.
For example, a storm in Bangladesh can drive millions of gallons of seawater inland, fouling water supplies and threatening farmland.
MAN (through translator): It's not just the cyclone. We're facing a disaster every day with water problems.
RAY SUAREZ: Kristie Ebi has written reports on climate change and health for the Intergovernmental Panel on Climate Change, the IPCC.
KRISTIE EBI, Intergovernmental Panel on Climate Change: There was a recent workshop in Bangladesh. As a part of that, there were field trips out to rural areas in Bangladesh where they are having saltwater intrusion, which is affecting the rice crops.
And, voluntarily, a farmer, an illiterate farmer, said: Climate change has a taste. It tastes like salt.
RAY SUAREZ: Sudden violent downpours will also be an increasing problem in wealthy countries with aging infrastructures.
DR. JONATHAN PATZ, University of Wisconsin: Many of our communities combine storm water with sewage, simply because it's too expensive to separate these systems.
This fight against global climate change...
RAY SUAREZ: Dr. Jonathan Patz is the director of global environmental health at the university of Wisconsin in Madison and also a lead author for the IPCC.
DR. JONATHAN PATZ: Every year, we get these combined sewage overflow events. Already, just with the type of rainfall intensity that we get today, we have over a trillion gallons that overflow into surface water, so, over a trillion gallons of sewage-contaminated water overflowing from simple rainstorms every year in the United States.
RAY SUAREZ: One example of this is New Orleans. Hurricane Katrina contaminated and shut down the municipal water system long after the storm had passed.
But, in places like Haiti, contaminated water brings typhoid and even death. But, as temperatures rise and climate zones shift, won't some places benefit as others suffer? Sure, says Jonathan Patz, the former Soviet Union will have a longer growing season, but he says losers will outnumber winners.
DR. JONATHAN PATZ: You know, a majority of agricultural areas will suffer, and that the adverse effects will outweigh the beneficial effects.
RAY SUAREZ: In developing nations, the increase in temperatures could affect the ability to be economically productive. As the world's poorest people try to work themselves out of poverty, the climates they live in are making it harder to work hard.
Dr. Tord Kjellstrom studies the effects of climate on work.
DR. TORD KJELLSTROM, Australia's National Center for Population Health: And as the only way to protect your body from overheating and getting heatstroke, which may even kill you, is to actually slow down work. It means that you are less efficient in the work you do. And you get less income. If you are an agricultural worker that is cutting sugarcane in Nicaragua, for instance, then you will produce less sugar per day if it's very hot, and you will get paid less.
RAY SUAREZ: Rising heat levels, according to Kjellstrom, is an added tax on the poor, who must work longer hours in the hot months to maintain meager incomes.
New seasonal patterns will force changes in daily life in the wealthy industrialized countries. Declining air quality and extreme heat will force people, especially the elderly, to remain indoors. And more CO2 will mean more allergy suffers.
DR. RICHARD WEBER, National Jewish Health: Ragweed is a major producer of allergy problems.
RAY SUAREZ: Dr. Richard Weber is an allergist at National Jewish Health in Denver.
DR. RICHARD WEBER: For the past several years, there have been reports coming out that the increase in CO2 means that the ragweed plants grow more vigorously. They have more above-ground biomass, which, in English, means they're bigger. OK?
They start pollinating sooner, so they flower earlier, and they produce more pollen. So, there's an increase in the amount of pollen that's being released into the air.
RAY SUAREZ: It doesn't end there. Dr. Weber said, explosive growth in grass pollens after heavy rains will flood the world's emergency rooms with asthma patients. Higher seas and higher humidity will bring more illness from mold spores.
While scientists point to thinning ice sheets and endangered habitats, the WHO's Maria Neira has two basic messages she hopes will come from the conference and spur a change in global behavior.
DR. MARIA NEIRA: Our message is, if climate change continues, the health of the people will be affected, particularly the health of the people -- the people living in very poor countries, but as well the health of the people living in very developed countries. Second message, to convince everybody that they need to do something about reducing carbon emissions is that is a commonsense thing.
RAY SUAREZ: The question is, now that the Copenhagen conference has pushed deadlines further into the future, will that message resonate with world leaders and change behavior fast enough to prevent what may be devastating health effects from global warming?