Top 10 climate technofixes

There's no shortage of ideas from scientists and entrepreneurs about how to deliberately manipulate the atmosphere to postpone the worst impacts of global warming. The following are 10 sci-fi-sounding methods that have actually been discussed or received research funding.

1. Imitate the planet-cooling effect of a volcanic explosion by pumping sulfur particles into the upper atmosphere.

2. Place mirrors or sunshade disks—“space mirrors”—between the Earth and the sun or in orbit around the Earth.

3. Use a fleet of sea vessels that continuously suck seawater from the ocean (hundreds of gallons per minute) to spray into the lower atmosphere. Updrafts would carry the particles higher and create “brightened” clouds.

4. “Plant” vast fields and deserts with artificial trees that remove CO2from the air.

5. Bury biochar (charcoal created from biomass) underground to affect carbon sequestration.

6. Fertilize the ocean with nanoparticles (iron, nitrogen or phosphorus) to increase the growth of phytoplankton and increase the absorption of CO2, which would then allegedly be carried to the deep ocean.

7. Paint cities and roads white or cover the desert with white plastic to reflect more sunlight back to space.

8. Flood Death Valley National Park with water to address sea-level rise and prevent flooding of populated areas.

9. Increase the ocean's “albedo” (reflectivity) by deploying floating reflectors (“ocean whitening”) or by creating “microbubbles.”

10. Genetically engineer crops to grow pale in color, reflecting sunlight back into space.