As the world's population hits seven million, freshwater resources are even more threatened by the effects of climate change. At the third "Changing Planet" Town Hall, held at Arizona State University, NBC News Chief Environmental Correspondent Anne Thompson interviews a panel of experts on how we can develop better, more sustainable water practices. Featured are Bill Richardson, Former Governor of New Mexico, Grady Gammage, Jr., Senior Sustainability Scholar at the Morrison Institute for Public Policy, Heidi Cullen, correspondent for Climate Central and Pat Mulroy, General Manager of the Southern Nevada Water Authority. This "Changing Planet" Town Hall was produced in partnership with the National Science Foundation.

In 2001, Drs. Bill Bradshaw and Christina Holzapfel at the University of Oregon became the first scientists to prove that recent global climate change is causing genetic adaptation in certain organisms. Their research over the past 30 years has focused on the pitcher plan mosquito and its changing response to the length of sunlight in a day. Changing Planet is produced in partnership with the National Science Foundation.

The wine industry is a multi-billion-dollar-a-year industry, but it could be in serious danger due to climate change. Scientists Grant Cramer and Anne Fennell are studying how different grape varieties respond to harsher conditions such as drought and spring frost. Their research could help vineyards and other farms that grow grape products, such as raisins, juice and fresh fruit. Changing Planet is produced in partnership with the National Science Foundation.

Millions of pine trees are dying in western North America, all due to a beetle about the size of a grain of rice. The mountain pine beetle uses pheromones, a chemical that attracts other mountain pine beetles, to successfully overwhelm a tree's defenses and kill it. Dr. Ken Raffa at the University of Wisconsin-Madison and Dr. Gary Blomquist at the University of Nevada, Reno are studying the beetle and how climate change is impacting its spread. Changing Planet is produced in partnership with the National Science Foundation.

Dr. Joy Ward at the University of Kansas is looking at how rising levels of carbon dioxide in the atmosphere may be impacting trees around the world and even causing them to adapt. By looking at ancient tree specimens from the Ice Age, Ward is able to see how trees in the past have adapted, helping her understand how trees may adapt today and in the future. Changing Planet is produced in partnership with the National Science Foundation.

Lizard populations around the world are in danger of going extinct. Dr. Barry Sinervo of UC-Santa Cruz explains that warming temperatures are to blame, limiting the amount of time the lizards have for gathering food and for reproduction. Changing Planet is produced in partnership with the National Science Foundation.

At George Washington University, NBC News Chief Enviromental Correspondent Anne Thompson and a panel of experts discuss how America can be transitioned away from traditional energy sources and towards a green economy. Included are Ken Zweibel, director of the Solar Institute at George Washington University, Phaedra Ellis-Lamkins, CEO of Green For All, Chris Busch, Director of Policy at the Apollo Alliance and Tim Juliani, director of Corporate Engagement at the Pew Center on Global Climate Change. This "Changing Planet" Town Hall was produced in partnership with the National Science Foundation.

With the threat of a warmer, wetter world and a larger global population, scientists are researching how climate change may impact the spread of infectious diseases, such as cholera and dengue fever, and how outbreaks may be prevented.  "Changing Planet" is produced in partnership with the National Science Foundation.

One of the bellwether species on the impact of climate change to our environment is the butterfly. Scientists say that warmer temperatures are affecting where butterflies live and breed, causing some species to migrate toward cooler climates near the earth's poles. "Changing Planet" is produced in partnership with the National Science Foundation.

In the past century, as the climate has warmed, sea level rise has accelerated. Scientists predict it will only increase, and they're studying changes in the ocean and land to better understand how and why the water is rising. "Changing Planet" is produced in partnership with the National Science Foundation.

Because of a warming atmosphere, permafrost -- the frozen ground that covers the top of the world -- has been thawing rapidly over the last three decades. But there is cause for concern beyond the far north, because the carbon released from thawing permafrost could raise global temeratures even higher. "Changing Planet" is produced in partnership with the National Science Foundation.

The world's glaciers are shrinking at alarming rates, and many scientists believe it is due to changes in climate. Dr. Lonnie Thompson of Ohio State University and Dr. Douglas Hardy of UMass-Amherst discuss glaciers and how they melt, and pay special attention to Africa's tallest mountain, Mt. Kilimanjaro. "Changing Planet" is produced in partnership with the National Science Foundation.

Black carbon, composed of tiny particles of soot, is produced whenever organic substances like fossil fuels, firewood or coal is incompletely burned. These particles are polluting the air and causing serious health and environmental concerns for people around the world. "Changing Planet" is produced in partnership with the National Science Foundation.

As higher amounts of carbon dioxide become absorbed by the oceans, some marine organisms are finding it's a struggle to adjust. "Changing Planet" is produced in partnership with the National Science Foundation.

Scientists are studying coral reefs around the world to discover the impact that warmer temperatures and increased carbon dioxide may have on the life cycle of corals. "Changing Planet" is produced in partnership with the National Science Foundation.

Bermuda may be known as a luxurious vacation destination, but it also houses one of the world's leading institutes for ocean studies, called BIOS. Dr. Tony Knap explains how climate change is causing ocean temperatures to rise, and what impacts it may bring around the world. "Changing Planet" is produced in partnership with the National Science Foundation.

As the global population continues to increase, scientists and farmers are concerned about the impacts that climate change could have on the world's crops. To better understand the process of photosynthesis and how plants use water and carbon dioxide to thrive, scientists are studying the stress limits of plants. "Changing Planet" is produced in partnership with the National Science Foundation.

Scientists studying lakes in northern and tropical latitudes are finding that rising lake water temperatures are affecting the ecosystems of the lakes. "Changing Planet" is produced in partnership with the National Science Foundation.

Scientists are watching the Arctic Ocean closely and measuring the growing amount of freshwater to see how it could affect the Earth's climate. "Changing Planet" is produced in partnership with the National Science Foundation.

Tom Brokaw joins a panel of experts at Yale University to discuss how climate change is affecting human health, economic opportunity and competitiveness and moral and religious values, as well as how young people are getting involved in finding solutions. Included in the discussion are Rajendra Pachauri, chairman of the IPCC and director of Yale's Climate and Energy Institute, Billy Parish, co-founder of the Energy Action Coalition, author Katharine Hayhoe, and Linda Fisher, the chief sustainability officer at DuPont. This is the full hour-long program, the first of three "Changing Planet" Town Halls being produced in partnership with the National Science Foundation.