Meat is a wasteful use of water and creates a lot of greenhouse gases. It puts enormous pressure on the world's resources. A vegetarian diet is better.
— Nicholas Stern

Each cylinder is about 10 percent ancient air, a pristine time capsule of greenhouse gases - carbon dioxide, methane, nitrous oxide - all unchanged from the day that snow formed and first fell.
Robert Lee Hotz on ice taken from bore holes in Antarctica greenhouse gases quote

Recent warming coincides with rapid growth of human-made greenhouse gases. The observed rapid warming gives urgency to discussions about how to slow greenhouse gas emissions.
— James Hansen

I've been vegan for 15 years, and it turns out it makes a very big impact on the environment to eat fewer animal products, which cause more greenhouse gases than all of transportation combined.
— Emily Deschanel

Since stepping down as laboratory director in 1999, I have devoted an increasing fraction of my time to international issues. I am involved with energy, environment, and sustainability issues, particularly as they involve new energy sources free of greenhouse gases.
— Burton Richter