Serious climate action addresses soot, particulates and black carbon first instead of CO2 since it would be cheaper, faster and more effective

Whatever happens to the global climate. There have not been serious or effective political action to reduce effects on the climate. Nothing Obama did was serious. Bush 2 stumbled into something that happened while he was president. Which was natural gas fracking. That helped but it was not because of policy targeted for environmental benefit.

Should there be serious actions ? Yes, that would be prudent.

CO2 would not be the first target if the world were serious about quickly impacting and reducing temperature trends.
It is 20 times cheaper to address particulates. It is faster and more effective

Particulates currently produce 80% of the temperature increase compared to CO2.
Particulates leave the atmosphere in 2 weeks. So if particulate production were reduced by 50%, then in two weeks the impact would start to occur.
Particulates are black and absorb more heat. They darken ice and increase ice melting. White ice would reflect more sunlight.

Euro 6 engine standards

The costs of fitting a GPF (Gasoline Particulate Filter) to meet Euro 6 limits have been estimated in a range of studies. The respected ADAC estimate the cost is just €50, whilst the Commission12 is more cautious with a range of €40 – 130. It reduces the particulates from a car by 1000 times.

The 15% reduction in the US CO2 emissions occurred because of cheap natural gas. Natural gas produces about half the CO2 to generate the same power compared to coal. Obama did not have a policy of encouraging natural gas fracking. The US did not ratify the Kyoto accords. The US was effective in reducing emissions when many who signed Kyoto were not.

The recent Paris climate agreement is based upon voluntary targets made and set by each country.

Note even with the Paris climate agreement China is still building hundreds of coal plants and plans to export coal power via high power lines to India and other countries.

I have written hundreds of articles on this topic and I researched all aspects of pollution and environmental impacts.

What would it look like if the world were serious about climate change ?

There are about 1.3 billion cars on the roads and 70 million new cars and trucks being made. Older cars, motorcycles, small engine devices like lawnmowers are the most polluting.
Have a policy of encouraging the early removal of older and more polluting cars. They have to get completely scrapped.
Have a policy of addressing particulates. Having GPF filters and other modifications retrofitted to the existing fleet of cars on the street.

Replace the coal burner at coal plants with cleaner technology. For the next 10-20 years natural gas or better a higher temperature nuclear reactors.
The turbine and grid connections remain. Just replace the coal burner or thermal source. Concentrated solar could be used to help reduce the amount of fuel that is burned.
Factory Mass produce nuclear reactors.
Uprate existing nuclear reactors with new metallic nuclear fuel with more surface area.
Increase battery and solar power by over 100 times.
Use more ride sharing and robotic cars

Follow the other soot reduction steps in UN recommendations.

No slash and burn agriculture go to slash and char. Slash and burn is currently causing horrible pollution in Dehli, India.

New Dehli, India, has shut down 1,800 schools for the first time ever, forcing a million students to stay at home to avoid breathing in the deadly smog that continues to shroud the city. This comes a week after firecracker residue from the Diwali festivities pushed the city’s Air Quality Index (AQI) into the red zone.

Levels of particulate matter (PM) 10 and PM2.5 hit 844 µg/m3 and 588 µg/m3 respectively on Nov. 06, according to data from the System of Air Quality and Weather Forecasting and Research (SAFAR), which monitors air quality. That’s shockingly above the safe limits of 100 µg/m3 and 60 µg/m3 respectively, and suggests that things have only worsened since last week when the “severe” pollution advisory was issued.

Steps against CO2 do not start bending any temperature curve for 30-50 years. Theoretically, it could happen within 20 but only with draconian measures that have zero chance of being enacted.