"I began to learn at least what other people felt and what they wanted to say before cutting them off with my own diatribe. I used to do that." - John Francis Andrew Heavens/TED hide caption

itoggle caption Andrew Heavens/TED

"Clouds are the most egalitarian of nature's displays 'cause we all have a great view of the sky" - Gavin Pretor-Pinney James Duncan Davidson/TED hide caption

itoggle caption James Duncan Davidson/TED

Pipes for Transcanada Corp.'s planned Keystone XL oil pipeline are stacked at a depot in Gascoyne, N.D. The House of Representatives approved the Keystone XL pipeline Friday; the Senate voted against it on Tuesday. Andrew Cullen/Reuters/Landov hide caption

itoggle caption Andrew Cullen/Reuters/Landov

Pipes for TransCanada's planned Keystone XL pipeline are stored in Gascoyne, N.D. The U.S. House has voted to approve the proposed project, which would allow crude oil to flow from Canada to the Gulf of Mexico. The Senate plans to vote Tuesday on legislation that would greenlight the project. Andrew Cullen/Reuters/Landov hide caption

itoggle caption Andrew Cullen/Reuters/Landov

Sherri Erkel and her daughter, Asa, cook dinner in their kitchen in Iowa City, Iowa. The Erkel family is part of an EPA study measuring the amount of food wasted in U.S. homes. Pat Aylward/NET News hide caption

itoggle caption Pat Aylward/NET News

Lightning strikes near Ben Hill Griffin Stadium at Florida Field in Gainesville, Fla., in August. A new study says a rise in average global temperatures due to climate change will increase the frequency of lightning strikes. Phil Sandlin/AP hide caption

itoggle caption Phil Sandlin/AP

A jogger goes for a run amid heavy smog in Shanghai on Wednesday. China has for the first time agreed to limit its carbon emissions, but critics are questioning whether the move goes far enough. AFP/Getty Images hide caption

itoggle caption AFP/Getty Images

California sheep rancher Dan Macon had to sell almost half of his herd because the drought left him without enough feed. Kirk Siegler/NPR hide caption

itoggle caption Kirk Siegler/NPR

Sen. Mary Landrieu, D-La., chair of the Senate energy committee, spoke Wednesday about getting congressional approval for the Canada-to-Texas Keystone XL pipeline. With her is Sen. Joe Manchin, D-W.Va., a member of the committee. J. Scott Applewhite/AP hide caption

itoggle caption J. Scott Applewhite/AP

Chinese President Xi Jinping and President Obama, seen here during a ceremony at the Great Hall of the People in Beijing, announced pledges to reduce greenhouse gases. HUANG JINGWEN/Xinhua /Landov hide caption

itoggle caption HUANG JINGWEN/Xinhua /Landov