Earlier this summer, Scientific American asked the presidential candidates questions on some of the "biggest scientific and technological challenges facing the nation."
You can read the candidates' answers here.
On climate change:
Obama: "I will continue efforts to reduce our dependence on oil and lower our greenhouse gas emissions while creating an economy built to last."
Romney: "I oppose steps like a carbon tax or a cap-and-trade system that would handicap the American economy and drive manufacturing jobs away, all without actually addressing the underlying problem. Economic growth and technological innovation, not economy-suppressing regulation, is the key to environmental protection in the long run."
Obama: "I will continue to work to strengthen our systems of public health so we can stop disease from spreading across our borders."
Romney: "A robust public health system is only as strong as the tools available, and I will empower the private sector to pursue the breakthroughs that will equip society for the health challenges of the twenty-first century."
Obama: "We will continue to operate the Space Station until at least 2020 and perhaps beyond. When our Orion deep space crew vehicle takes its first test flight in 2014, it will travel farther into space than any spacecraft designed for humans has flown in the 40 years since our astronauts returned from the moon."
Romney: "A strong aerospace industry must be able to compete for and win business in foreign markets. I will work to ease trade limitations, as appropriate, on foreign sales of U.S. space goods and will work to expand access to new markets."