Björn Lomborg: Europe's sceptical environmentalist

World leaders will disembark from carbon-spewing jets in New York on Earth Day this Friday to sign the Paris climate treaty, the world’s costliest-ever accord.

Watching the news, you get the sense that climate change is making the planet unlivable. We are bombarded with images of floods, droughts, storms and wildfires.

Climate change is clearly an important global issue, but we are tackling it very badly and our overwhelming focus on reducing carbon emissions also distracts us from many of the world's most pressing problems. What makes it so hard to cut emissions is that CO2 is a byproduct of prosperous economies, and replacing cheap fossil fuels with today's mostly expensive and unreliable green alternatives remains incredibly expensive. An analysis for the government of New Zealand recently showed that achieving carbon neutrality by 2050 would cost the nation 16% of GDP.