A number of hypotheses have been used to explain how free oxygen first accumulated in Earth’s atmosphere some 2.4 billion years ago, but a full understanding has proven elusive. Now a new model offers ...

In a new report, the United Nations Environment Program (UNEP) concludes that global warming is expected to exceed 1.5°C ...

Aerosols have a profound influence on air quality, human health, clouds and climate, but new particle formation in the ...