April 22

On April 22, 1970, the inaugural Earth Day united millions across the United States in advocating for environmental protection. Organized by Senator Gaylord Nelson, the event featured rallies, teach-ins, and community cleanups. It sparked the modern environmental movement, leading to the creation of the Environmental Protection Agency (EPA). Landmark legislation, such as the Clean Air Act and Clean Water Act, followed in the years after. Earth Day has since grown into a global observance with activities in over 190 countries.

Negotiated under the United Nations Framework Convention on Climate Change, the Paris Agreement unites nearly 200 countries in a collective effort to keep global temperature rise well below 2°C above pre-industrial levels, with an aspirational target of 1.5°C. Each signatory commits to national reduction targets known as Nationally Determined Contributions (NDCs), which are reviewed and strengthened every five years to accelerate climate action. The treaty also established frameworks for financial support, technology transfer, and capacity building to aid developing nations in mitigating emissions and adapting to climate impacts. Opening signatures marked an unprecedented diplomatic achievement in environmental governance, demonstrating global solidarity against a shared threat. The agreement entered into force on November 4, 2016, after surpassing the required ratification thresholds, solidifying its role as the cornerstone of modern climate policy.