The Adelie penguin colony at Cape Royds, Antarctica, is already feeling the impact of global warming - and that's where CBS News correspondent John Blackstone first met penguin researcher Jean Pennycook earlier this year. She was worried.
"If the ice goes away, these penguins will no longer be able to survive," she said. "So as we see the ice decrease, the penguins will struggle to exist."
When she's not in Antarctica observing the penguins, Pennycook teaches about them in Fresno, Calif.
"So this was more melting than we'd ever seen before - and it was because it was a warmer year," Pennycook said to a class.
She shows her photos of penguins flooded out by fast-melting glaciers. Ice loss in Antarctica has increased by 75 percent in the last dozen years due to global warming.
"How many of you think that to save the penguins, you'd be willing to walk to your friend's house rather than take the car?" she asked her class.
One hundred miles north of Fresno, near Modesto, Calif., John Fiscalini would like to be part of the global-warming solution. But for now his 3,000 cows are part of the problem.
Each cow produces plenty of milk.
"They're basically giving 85 to 100 pounds of milk a day," Fiscalini said.
But cows also make methane, a potent greenhouse gas. The United Nations calculates livestock are responsible for 18 percent of greenhouse gas emissions worldwide - even more than cars.
"They have just been escaping up into the environment and contributing to climate change," he said.
So Fiscalini has called in Brian Gannon, who builds methane digesters that capture the gas.
The methane from 300 tons of manure a day will go through a generator making enough electricity to run the whole farm - with power left over to sell to the local utility.
Both presidential candidates are pushing pollution-cutting efforts like these. Just recognizing climate change as an issue is a big change from the past eight years.
Both candidates say they'll join international climate change efforts that the Bush administration has ignored, and will press China and India to cut greenhouse gases.
Back home, both would start with modest greenhouse gas reductions - then increase cutbacks for 40 years into the future.
McCain said while in Santa Barbara: "Until we have achieved at least a reduction of 60 percent below 1990 levels by the year 2050."
Obama goes further.
"I've put forward very substantial proposals to get 80 percent reductions in greenhouse gasses by 2050," Obama told CBS News.
Both would reach those goals largely thru a "cap and trade" program that works like this:
"Leadership must begin at home. That's why I've proposed a cap and trade system to limit our carbon emissions and to invest in alternative sources of energy," Obama said in May in Miami.
And McCain, in Santa Barbara, said: "I have proposed a new system of cap-and-trade that over time will change the dynamic of our energy economy."
The candidates sound the same, but there are differences.
McCain would give companies most of the emissions permits for free based on their previous emission levels. Then if they cut back, they can make money selling unused permits.
He said in Portland. "In all its power, the profit motive will suddenly begin to shift and point the other way toward cleaner fuels, wiser ways, and a healthier planet."
Obama would sell all emission permits at auction, so companies would have to pay for every ton of carbon they release. Money raised would be used to develop renewable energy and to subsidize consumers' energy bills.
By one estimate a cap and trade program could raise the average family energy bill more than $700 a year.
In the August, 2007 Democratic primary debate, Obama said: "There are some things that we can do to conserve energy, but all those steps are going to require a little bit of hardship and a little bit of pinching."
None of this clean energy comes cheap. Just ask John Fiscalini.
His new generator alone cost $1 million.
So he's glad both McCain's and Obama's cap and trade program would give him credit for greenhouse gases he's capturing … so he could sell them to a company that needs more pollution permits.
"I just happen to be one of those people who kind of enjoys being out in front of the pack," he said.
Jean Pennycook knows whoever is elected, the Antarctic ice is unlikely to stop melting anytime soon. But she's relieved the next president won't deny it is happening.