Umair Irfan
Former correspondent
Latest articles by Umair Irfan
How just one case of coronavirus could lead to thousands more if we all don’t limit social contact.
Older people and people with chronic illness are at greater risk, and how we respond to the threat affects everyone.
Viruses like the one causing Covid-19 are a tricky target for medicine.
Normally packed streets, museums, and venues around the world have fallen silent amid the deadly outbreak.
The controversial tactic to fight against climate change is becoming increasingly popular among companies, countries, and travelers.
Offsets have become a wildly popular — and controversial — way to fight climate change.
The billionaire former New York mayor funded a successful program to close coal power plants. But activists say his plans for the future lack ambition.
What we’ve learned about his climate change agenda on the campaign trail.
Several candidates say they will stop all new fossil fuel leases on public lands.
Several ideas for improving climate security.