Global heating and its partner, ocean acidification, are more important than any of the other things we are now worrying about. This is my attempt to summarize what I have learned.
     Around our planet wraps an exquisitely thin film of air, water, and soil. Inside this film is all the life we know of. The planet is eight thousand miles wide, the air is just a few miles thick, and outside it is the cold vacuum of space.
     Conditions in the life-supporting film have rather suddenly started changing. The air is heating, and the ocean is acidifying.
     Both trends are caused by increasing quantity of carbon dioxide gas in the atmosphere. That extra gas is being pumped into the atmosphere by us.

The basic science
     The atmosphere was once full of carbon dioxide. Plants replaced most of that with oxygen, which animals can breathe.
     Greenhouse gases, including carbon dioxide, control the atmosphere's temperature.
     The amount of carbon dioxide in the air is drastically increasing.
     The temperature of the atmosphere is therefore rising.
     Carbon dioxide driven into the ocean is acidifying it, which is dire for the life in it.
     The permafrost across northern continents is thawing and releasing jets of methane — a terrible feedback loop and a starkly visible symptom of global heating.

Does it matter? Won't it be rather nice to get warmer? No. We're heading for a desert world.
     Ice and snow cover are dwindling, glaciers are in retreat, the Greenland and Antarctic ice sheets are shrinking.
     The global ocean is rising.
     There will be more extreme weather: storms, droughts, heatwaves.
     Climate and vegetation zones are shifting; seasons are changing.
     Deforestation feeds the heating.
     Plants and animals are affected. There is a global extinction going on.
     Climate refugees are pressing from the worst affected countries into the “lifeboat” countries.

The argument. There is really no argument within the serious scientific community, but.those who profit from business as usual have been able to confuse the public with spurious arguments.
     Is it just the sun?
     Have we been saved by a sudden change to cooling?
     It's cold here! — where's global warming when we need it?
     Mistake on page 493.
     A conspiracy — on which side?

Solutions, besides the obvious ones of slashing our vast emission of carbon dioxide from industry and transportation:
     Geo-engineering, is it the remedy?
     Perennial varieties of food crops would store carbon, besides saving water and fertilzer and tilling, and increasing yield.
     Vertical farming inside cities can bring food close to where it is needed, save fuel, and let landscape return to nature.
     Meat derived from a few stem cells instead of from millions of slaughtered animals could massively reduce methane, deforestation, and human afflictions such as "mad cow disease".
     Ocean algae can be managed so that, using solar power, they provide bio-fuel while capturing carbon out of the atmosphere.
     The successful precedent: the ozone hole.