The weather experiment that really flooded Dubai

• That was the story last week when more than a year’s worth of rain fell in a day on the Arabian Peninsula, one of the world’s driest regions.
• Desert cities like Dubai in the United Arab Emirates (UAE) suffered floods that submerged motorways and airport runways.

• Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue.
• Richard Washington, a professor of climate science at the University of Oxford, has seen the inside of a storm.
• To confirm if cloud seeding really could breed record-breaking rain, he once boarded an aeroplane bound for a thundercloud over the South Africa-Mozambique border.

What caused the flood?

• But by flying a lot of missions, half with cloud seeding and half without, and measuring rainfall between the two, meteorologists eventually showed that cloud seeding did modify rain rates in some storms.
• That’s not what caused Dubai’s floods though.

• Their approach is to fire hygroscopic (water-attracting) salt flares from aircraft into warm cumuliform clouds,” Washington says.
• “So could seeding have built a huge storm system the size of France?
• Let’s be clear, that would be like a breeze stopping an intercity train going at full tilt.

The experiment of our lives

• Although last week’s deluge was unusual, the Arabian Peninsula does tend to receive more of its precipitation in heavy bursts than steady showers.
• What is likely to kill more people as temperatures rise in this part of the world is not water, but heat.
• At this threshold the air is so hot and humid that you cannot lower your temperature to a safe level by sweating.

• Peter Irvine, a lecturer in earth sciences at UCL, proposes dimming the sun by pumping microscopic particles into the upper atmosphere to reflect some of its rays.
• These layers of gases that surround our planet have nurtured life by keeping temperatures stable and harmful radiation out.
• Read more:
  Time is running out on climate change, but geoengineering has dangers of its own

  As humanity contemplates another large-scale experiment in our atmosphere, there is another, even bigger one, waiting to be resolved.