Four more nations ratified the Paris Agreement on climate change in December, bringing the number that have done so to 121.
Kazhakstan notified the United Nations of its formal adoption of the accord on Dec. 6.
Zambia was next, formally agreeing to the Paris Agreement on Dec. 9.
Cuba and Kenya ratified the landmark Dec. 2015 international agreement on Dec. 28.
The Paris Agreement took effect Nov. 4, 2016. Adopting nations agree to prepare Nationally Determined Contributions to the reduction of atmospheric greenhouse gases.