Climate change is real, but Paris treaty won't fix it

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.

No doubt, American presidential candidates will use the spectacle to make hay. In line with President Obama, Hillary Clinton believes the treaty is a “historic step forward” against “one of the greatest challenges” of our age, while Bernie Sanders argues it “goes nowhere near far enough.” John Kasich has “serious concerns” the agreement will hurt the American economy; Donald Trump is not a “great believer” in man-made climate change and might ditch the treaty; Ted Cruz says he’d do the same because it was agreed by “ideologues”.

Amid this political back-and-forth — man-made climate change is not real, or it is the worst threat facing humanity; the treaty is horrendous, or it is great — the facts are easily lost.