A historic signing at the United Nations to combat climate change.

FOX's Jared Halpern has more:

On Earth Day more than 150 countries are formally signing the Paris Agreement. A climate change pact negotiated months ago, aimed at slowing down the rise of global temperatures:

(Moon) "We are in a race against time. I urge all countries to move quickly to join the agreement at the national level."

U.N. Secretary General Ban Ki Moon calls the signing ceremony record breaking though it is partly symbolic.

Many countries still have lengthy ratification processes and thresholds to limit carbon emissions are up to each country and non-binding, so there are no specific consequences.

Still it earned widespread support, including from China and the U.S.

Jared Halpern, FOX News.