Unreliable car emissions tests harming fight against air pollution, expert says

On the road and lab test discrepancies undermining efforts to curb toxic air levels as UN environment assembly admits global response is not up to scratch

World could warm by massive 10C if all fossil fuels are burned

Arctic would warm by as much as 20C by 2300 with disastrous impacts if action is not taken on climate change, warns new study

Gloucester cathedral’s zero-carbon footprint

Letters: We should be able to generate around 25% of the main cathedral electricity from our new panels, including power for our air source heat system

How much do you know about bees? – quiz

Despite our professed concern for bees, a YouGov poll for Friends of the Earth found that most of us can’t recognise a honey bee. Take the green group’s quiz to see how much you know

• The Great British Bee Count take place from 19 May-30 June

Great Barrier Reef needs $10bn for chance of survival, scientists say

This election is Australia’s last chance to save the reef, which requires $1bn a year for 10 years to reduce water pollution to give it a chance to survive climate change, report warns