Could future presidents unravel the commitments to cut emissions the US has made at the Paris climate summit?
How will the world actually deliver on the Paris climate ambition to hold global warming to no more than 1.5℃? It's a tough scientific and technical challenge.
The Paris climate summit was historic as a political achievement but it's not clear how and when the hard problems of emission cuts and climate finance get tackled.
Countries have signed up to the Paris climate deal, but they have not yet promised the necessary cuts to emissions.
COP21 ended with an agreement that is at once both historic, important – and inadequate
The climate will change, no matter what's agreed in Paris.
Think Arctic, think stranded polar bears? There's more to it than that.
Even oil companies have started asking for a price on carbon, not least because it could help them avoid other, stricter forms of regulation.
The country must protect its huge forests from fires and logging.
1.5 or 2 degrees? What matters is how we get there.
The media prefers positive stories to the traditional doom and gloom of climate coverage.
Things can change disturbingly quickly – just ask the people who once farmed the Sahara.
A majority of countries want visionary action rather than pragmatism at the Paris climate talks, says the International Institute for Environment and Development's Saleemul Huq.
How to hit rogue countries where it really hurts – in the wallet.
A key sticking point may be resolved at the Paris climate talks: but at what cost to developing countries?
Advertising takeovers and creative forms of disobedience are some of the few means left to contest who is allowed to maintain a public voice at COP21.
Since scientists are the real sceptics, they still argue a lot among themselves.
Strength in numbers matters in the world of solar energy.
At the halfway mark in the Paris climate talks, progress is still frustratingly slow as the negotiations risk falling prey to old stalling tactics.
A new survey shows that many Pacific islanders are considering migrating to escape climate change. It's time for new international rules to manage the flow.
Former NASA climate scientist James Hansen has come to the Paris climate talks to push his radical alternative to current carbon pricing schemes.
NASA once had 400,000 people working on space exploration. We should battle climate change in the same way.
The food on our tables is central to the #COP21 debate and any Paris agreement must help build a system that moves us a long way from our current habits.
The Paris Climate Conference must not be hijacked by big business and its allies in the world's media.