Satellites discover huge amounts of undeclared methane emissions

The sources of methane release are pretty varied, for example damming rivers can be a line source, as it increases the water level upstream from the dam, submerging trees/brush which partially break down into methane.

It’s a fascinating space really. Earth observation from satellites is going to reveal a lot of insight about the world.

If all the HVAC equipment in use were vented, it would be like 200 ppm of CO2. Meaning, even if you got CO2 all the way to zero, you would not get to the pre-industrial level of heat forcing; and good luck ever scrubbing it out. Thus far, fluorine compounds already in the atmosphere amount to 40 ppm CO2 equivalent. So it is critical to capture and incinerate the HFCs already in use. A substitute for them is supposed to roll out in a few years.

Just one kilogram of SF6, used in high-voltage electrical equipment (including wind turbines) is equivalent to 25 tons of of CO2. HFCs are about a tenth that, but there is a lot of it. Most of the CFCs already vented, up to the time they were mostly banned, are still there. Some places still vent them.

Right now the biggest fluorine-compound polluters in the US are three companies involved in supporting chip manufacturing. They probably have counterparts in Taiwan, Korea, and China.

There is new substitute for SF6, and an ongoing effort to pump out and dispose of it, in US equipment.