What's worse for disease spread: animal loss, climate change or urbanization?

Scientists have long known that human activity often helps pathogens spread.

Human-caused climate change can push disease-carrying mosquitoes or ticks into new places as temperatures rise, and deforestation can expose humans to viruses circulating in once-isolated species. But despite hundreds of studies investigating human influence on infectious diseases, scientists weren't sure whether certain activities matter more than others for increasing risk.

Now, new research clarifies that picture – and suggests that humanity's reshaping of the planet is stoking the spread of dangerous infectious diseases not just for people but also for other animals and plants.

Climate change, the spread of invasive species and the loss of biodiversity (when species decline or go extinct) are all triggers that worldwide, according to an analysis of existing research published this month in . The study found these changes had fairly consistent effects on the spread of infectious diseases regardless of geographic location or species, underlining the need to reduce greenhouse gas emissions and conserve biodiversity, scientists say.