Ep 14. Can We Cool the Planet?

In the latest episode of NOVA season 49 episode 14, titled "Can We Cool the Planet?", the show explores the rapidly growing field of geoengineering - the deliberate manipulation of Earth's climate to counteract the effects of global warming caused by greenhouse gas emissions.

As Earth's average temperature continues to rise due to human activity, scientists are increasingly looking for ways to mitigate the impact of climate change. Geoengineering offers a potentially powerful solution, but it also presents significant ethical and environmental challenges.

The episode begins by examining one form of geoengineering known as solar radiation management, which involves reflecting more sunlight back into space to reduce the amount of heat trapped by the atmosphere. One proposal for achieving this is to launch reflective particles or mirrors into the upper atmosphere, which could reduce the amount of sunlight reaching the Earth's surface.

However, this approach has a number of potential risks and unknown factors. For example, it's unclear how much of an impact reflective particles would have on Earth's climate, and there are concerns that they could interfere with weather patterns, alter ecosystems, and even cause unintended health effects in humans.

To explore the implications of geoengineering, NOVA speaks with leading experts in the field, including scientists and policymakers. The show examines the history of geoengineering and how it has evolved over time, as well as the different approaches being considered today.

These include not only solar radiation management, but also carbon dioxide removal techniques such as bioenergy with carbon capture and storage (BECCS) and ocean fertilization. BECCS involves growing crops like trees that absorb carbon dioxide and then burning them for energy while capturing the carbon dioxide and storing it underground, while ocean fertilization involves adding nutrients to the ocean to stimulate the growth of carbon-absorbing plankton.

NOVA weighs the potential risks and benefits of each approach, examining the ethical, legal, and social implications of geoengineering. The show also explores how different nations and organizations are approaching the issue, from the United Nations to private companies like Bill Gates' Breakthrough Energy Ventures.

Ultimately, NOVA presents geoengineering as a potentially powerful tool for mitigating the effects of climate change, but one that must be approached with caution and careful consideration. The show provides a fascinating introduction to the world of geoengineering that will leave viewers with a greater understanding of this complex and important issue.