Hi, I agree that the focus on greenhouse gases might not be the best. Rather let us focus on a continuous reduction in our use of irreplaceable fossil fuels.
We can do this easily if an additional tax is placed on all the fossil fuels to encourage all humans to use less of them. This tax, I recommend 10% to start with increases every year of a few more percent, would generate revenue which could be given out in loans to people or organizations that will provide either alternative energy
sources or good conservation improvements.

Possible things to be funded?

1. Mid-Atlantic ridge based thermal electric plant (tap the earth's internal heat), making local use of the electricity to produce cement or other products that use large amounts of energy.

2. Solar power stations in space.

3. Large solar stills in Africa that can produce fresh water from sea water and also electricity.

4. A large geothermal power plant with a deep large bore pipe into the earth in the eastern United States. Providing both electricity and heating for cities in area.

5. Repair or removal of large numbers of inefficient buildings and replacement by new efficient buildings.

6. Improved transportation systems.

The list could go on forever, by the way 10% of the money the world spends on fossil fuels is a lot of money.

Your letter goes no where near far enough - emissions are but a symptom and we must address the cause. As a youth I doubted our behaviour when, in the 1960's, I was confronted with how different societies resolved their transport needs, Americans with the 2-ton Chevy and the Europeans with a Morris 850 or Renault 4.
On qualifying as an electrical engineer in 1967 I set out to develop a sustainable air-conditioning system (solar absorption). The concept was defeated by economics; why have expensive solar collectors when one could burn free coal and oil etc.
In the 1970 my partner and I attempted to design a sustainable home but found that (other than incorporating thermal mass through inverse brick veneer, plenty of insulation, and solar hot water,) adoption of most sustainable construction, energy and water activities were beyond our means or the sacrifices we were willing or able to make. Sustainable activities should have been the first option but economics dictated otherwise.
Why is it so? Why do we blindly conform to a nonsense economic model when if our economics was measuring the truly significant variables our behaviour would automatically be sustainable?
As an engineer I analyse and manage systems. System boundaries are placed where inputs and outputs can be readily measured, this makes management possible. With an Earth system boundary just outside our atmospheric layer inputs are solar radiation and lunar and solar gravity.
Sustainable activity requires that we can do it again using these system inputs.
That we shall make many of the Earth’s resources inaccessible within 300 years of the industrial revolution clearly demonstrates we are not doing this.
Greed is blamed but this is futile while our economic system unilaterally rewards such activity. Overpopulation is also said to be causal but economics requires we grow our population to grow our economy; circular nonsense!
We cannot address these problems while the economic system is fatally flawed? Economics ignores the significant variables, defining natural resources as of zero value, and only costing the human inputs of extraction or destruction. Thus our most important resources are outside the fundamental supply/demand cost function we use to manage far less meaningful variables. Further the free-market only serves those present to bid; the future (including future generations) shall have nothing to bid on.
Our problem shall not be solved by addressing symptoms (such as greenhouse gasses with the likes of emissions trading), but by the imperative reform of our economic system.
NOTE: For an activity to be sustainable the time for Production of the natural resources involved within system Earth must be less than the time for which they are Used; i.e. P(t)/U(t)<1. This is the Produce Use Sustainability Index (PUSI) and the key to the new economics. Growth is a dangerous concept when you are not measuring the relevant.