Humans have caused 1.5 °C of long-term global warming according to new estimates

On the order of 100-200 trillion USD. Which is roughly 100-200% of global yearly GDP. Or 2-5% of yearly GDP until 2050. This could well be provided by printing money at all the federal reserve banks.

This investment will likely bring in a positive return on investment because it reduces the negative climate impacts.

Without such investments the downstream costs in climate change adaptation will be very expensive

TL;DR is three major factors:

1. The agencies that are doing the estimates are _very_ bad at exponential development curves (cough cough IEA estimating solar [2])

2. Unfortunately much of the developing world's economy is not growing as fast as we previously thought it would (similar thing happening with birthrates)

3. Many costs are absolute and _not_ marginal, which is just wrong IMO. We are going to need the energy either way, we should be talking about the "green premium" (as far as it exists), not how much it'll cost to generate XX TWH of energy

[1]: https://www.economist.com/interactive/briefing/2024/11/14/th...

[2]: https://www.economist.com/interactive/briefing/2024/11/14/th...

If you turn off your gas generator and replace it with solar + batteries, you will spend the entire cost of solar + batteries plus the decommissioning cost of gas (that may be negative if you can sell some parts) to go back to exactly the same point you were before.

So, no the cost is only marginal if you accept you will follow the depreciation curve of you infrastructure. And that's way too slow to reach the goal.