Limiting human-induced warming will be tough, given where we start from.
Canada ratified the Paris agreement on climate change, but it hasn't yet filled the leadership void left by the United States. Time is running out.
Phasing out greenhouse gas emissions entirely by mid-century is possible, and promising trends are emerging. But the next five to ten years will be the real test of whether we can make that happen.
1.5 or 2 degrees? What matters is how we get there.