Explainers

The background behind the good news

Short explainers on the goals, terms and processes that come up in our stories, each built from official sources and linked to the latest news on the topic.

• Clinical TrialWhat are the phases of a clinical trial?New drugs are tested in people in phases, from small safety studies in a few dozen volunteers to large trials with thousands of patients. Each phase answers a different question, and most drugs that enter Phase 1 never reach approval.
• Endangered SpeciesWhat do the IUCN Red List categories mean?The IUCN Red List sorts species into nine categories, from Least Concern to Extinct, based on how close they are to extinction. More than 49,500 of the 175,900 species assessed, 28%, are threatened.
• Protected AreasWhat is 30x30? The goal to protect 30% of land and sea by 203030x30 is the global target, agreed by governments in December 2022, to have at least 30% of the world's land and 30% of its ocean effectively conserved by 2030. By October 2026, protected and conserved areas covered 18.69% of land and 10.04% of the ocean.