Clinton will keynote the summit put on by Sen. Harry Reid and Center for American Progress.
The Louisiana Democrat plans to hold a hearing on Keystone XL in May.
The American Public Health Association and the National Association of County and City Health Officials are seeking a health study of Keystone XL, which two senators said would increase cancer risks.
The Rhode Island Democrat hopes to make climate change a wedge issue in 2016.
The rate at which greenhouse gas (GHG) emissions grew in the first decade of the 21st century was almost double the yearly rate from 1970 to 2010, the United Nations said in a draft report obtained by the Guardian.
Sweden-based furniture retailer Ikea has bought an under-construction wind farm in Illinois, the first United States wind farm for the company.
"We need a definitive timeline laid out," 11 senators wrote.
A Senate panel on Thursday questioned the impact of the Obama administration's climate rules on the reliability and security of the electric grid.
Thursday’s action will move the Interior Department toward a more predictable process for judging development and mitigation.
The process will continue "without interference," the administration said.