Very strong evidence from our butterfly monitoring schemes that butterflies are emerging earlier in the spring, and very strong evidence that trees are leafing earlier in the spring as well. Environmentalists say industrialized nations urgently need to cut carbon pollution released by the burning of coal, oil and gas. Nations should shift away from fossil fuels to renewable sources of power, and step up the search for alternative sources of energy. Passenger jets already emit a lot of carbon dioxide. And climatologists say things will likely get worse.
Tourism is poised to overtake the oil industry as the world's largest industry.
The new study predicts the number of tourists is likely to triple by 2020, to more than 1.6 billion people.