I've played this a few times, and I finally turned everything 100% green with a few turns to spare. I figured I would have to keep going until time ran out, so I focused on managing unemployment. Then, right before the end of the game, a random event caused one region to lose some of its green energy, so I wound up in an unwinnable situation even though I had played well. It really felt like this game should have been in the bag.

Ah, so I managed to continue the game before the disaster, and it looks like there was a single pixel of ungreened energy in one of the circles. It was extremely difficult to tell that it was even there, or what color it was supposed to be.

My suggestion would be to add some kind of display on hover (maybe at the bottom?) showing the actual percentages of each type of energy in a region. Alternatively, some kind of marker (a star?) when a region has actually achieved 100% green energy.

I really enjoyed this game! Great work!

This almost sounds like a bug, but it could also be because the win condition is more than the sum of Green Energy from all the regions.  There are a few cards that directly lower the Carbon Bar, without actually moving the percentages of the regions.  After playing a few of these, I was able to win without maxing out green energy of every region.  

I had a similar bug happen to me. If you reduce your emissions to zero the moment time runs out the game counts it as a loss. 

In 2022 we have already increased the global average temperature by 1.3 °C (compared to preindustrial levels). Reducing all emissions to zero would make the natural carbon capturing processes dominate and CO2 concentrations decrease for some decades. In this scenario, however, the global average temperature is predicted to stay roughly constant, the adverse effects of climate change we are experiencing today not alleviated. To restore the average temperature to preindustrial levels, large-scale carbon capturing methods will be necessary.

In the game, it is necessary to research and build these carbon sequestering solutions to reduce the carbon bar on the right to zero. To me, this seems intentional.