One aspect of climate change that is often missing from our conversation is how much of it is already locked in.
Until we find some mechanism to extract atmospheric greenhouse gases, not just a lot of CO2 but a big percentage of it, most of it, a massive amount of CO2, those persistent gases will continue to warm Earth's climate well into future centuries. At present we're still adding to it.
One certain victim will be the glaciers of the Himalayas. A new report warns that one third of those glaciers is doomed even if we miraculously adopted radical emissions cuts. Glaciers, so what? Well those glaciers are the source of the Himalayan headwaters, a main source of fresh water for three nuclear powers - China, India and Pakistan.
China, of course, occupies Tibet. That gives Beijing the whip hand over future access to a lot of that vital Himalayan water. That's more critical than ever now that climate change has made the annual Monsoon rains unreliable and unpredictable.
Even if carbon emissions are dramatically and rapidly cut and succeed in limiting global warming to 1.5C, 36% of the glaciers along in the Hindu Kush and Himalaya range will have gone by 2100. If emissions are not cut, the loss soars to two-thirds, the report found.
The glaciers are a critical water store for the 250 million people who live in the Hindu Kush-Himalaya (HKH) region, and 1.65 billion people rely on the great rivers that flow from the peaks into India, Pakistan, China and other nations.The graphic at the top shows the great rivers of south and east Asia fed by the Himalayas - among them the Indus, the Ganges, the Brahmaputra and Irrawaddy, the Mekong, and the Yellow and Yangtze. What could possibly go wrong?