Debate, really? While some people blather on debating the existence of climate change, the climate is busily changing around us. The debate really is: Are we going to try to stop or at least reduce it, or just blunder along until it slaps us in the face?
The answer should appear obvious. However, here is an examination of what we could do, planet-wide, to adapt if we choose to do nothing.
Some basics: Greenhouse gasses trap heat, thus their name. We are emitting CO2 and methane at rates unparalleled in history, thus we are trapping heat in the atmosphere. Heat is energy. What is essentially happening is that we are adding energy to the weather system. Storms are getting more violent. Cold snaps are colder, and more unpredictable. Rain patterns are shifting. Winds are stronger and more frequent. In general, the climate is getting wilder and somewhat warmer on average.
Areas that were reliably moist before will experience drought. Dryer areas will experience flooding. And as the climate has more energy, those area may change from drought to flood more suddenly and less predictably. Sudden storms with strong winds and tremendous hail will become more common. Because of the increased energy, there will be greater evaporation from the oceans, thus more moisture in the weather patterns altogether, but precipitation will be concentrated more densely. Therefore where it does rain and snow, there will be greater rainfall and snowpack. On the other hand, higher winds will drive those weather patterns farther before they precipitate. In other words, floods will be deeper and droughts dryer.
How to adapt?
Water supply: In the long run the only way to adapt will be to run tens of thousands of miles pipelines to move water from flooding areas to drought stricken areas. These areas may shift and alternate unpredictably--better make those pipes capable of flowing both ways.
Agriculture: Prepare massive seed stockpiles strategically all over the world to be able to plant whatever crops the climate of a region will support that year. Prepare to move land in and out of production or change the crops at the drop of a meteorological hat. What may be the perfect area for rice paddies one year may be perfect for coffee the next--or cactus fruit. Forget crops that take more than one year from planting to harvest. Fruits and nuts will be in short supply, but supplanted with grains and beans.
Construct millions of square miles of roofs over crops to protect them from storm damage. No matter how perfect the weather for a crop is one season, a single tornado or massive hail storm can destroy it in an afternoon. Hey while we're at it, why not make those roofs solar collectors? Might as well use some free energy to power all the water pumping.
Cities: Move all our cities a few miles back from watersides, or elevate the cities above the new, higher flood levels. Also we ought to elevate our roadways, put wind breaks along both sides of every road, and both raise and strengthen ALL our bridges.
Conclusion: If we invest at most a few dozen times the combined annual economic product of the entire planet, we can adapt to climate change easily. For a few years.