• it is possible, but should we
• may have unintended consequences that are irreversible
  
• may be possible only on a very limited scale
• what science does: observe, predict, experiment, control--people in the 1950s believed that with science nothing was impossible
  

Experiments with weather modification

• the public quickly accepted this was possible--they were that in awe of the power of science
• some scientists believed would be able to change life for the better by controlling weather
• cloud seeding with dry ice, silver iodide, sodium chloride
• it was possible on a small scale, but only a few scientists believed it was possible on a large scale
  
• it only worked with clouds that were in the right state--ready to rain--so how to know if it would have happened anyway?
• people then feared the experiments had caused unusual weather that had caused a flood in Canada
• meteorologists took the stance that we don't understand the weather enough to modify it

reactions:

• fear of unintended consequences
• are the forces involved in weather too large for humans to modify?
• what are the biases of the experts?
• different assumptions in people's heads
• weather is an act of God, we can't possibly modify it
• science and technology progresses towards complete control of nature
• we shouldn't try to modify the weather
• because it is too complex so too much danger of unintended consequences
• we shouldn't disturb the balance of nature
• we have a responsibility to preserve the natural world undisturbed
• if we could turn the whole earth into a garden modified for our own benefit, should we?
  

but nuclear tests in 1954 showed that humans could have large scale effects

• weather was abnormal around the world that year
• meteorologists refused to believe it was caused by ground level nuclear tests, but the press kept reporting speculation
• a moratorium on atmospheric testing was observed 1958-early 1962, then there was a flurry of testing, then a treaty was signed in 1963
  
• high altitude tests in 1958 and 1962 increased the size and strength of the Van Allen radiation belts around the earth
• this shifted the thinking of scientists, human action changing the world on a world on world-wide scale was possible
  
• whether they affected the weather seems more still a matter of debate
  

what does this say about how we think about our relationship with nature?

• could we control something as large scale as the weather
• if we could, should we?
• US research apparently ended in 2005 but cloud seeding is practiced on a small scale: 55 projects in the US in 2014
  
• in a larger scale in some other countries: "There’s even a luxury cloud-seeding market emerging—one European company, for instance, charges a minimum of $150,000 to guarantee good wedding weather by forcing clouds to rain in the days before the event."
• legal issues
• makes it seem more possible that we could be doing world scale damage unintentionally
• should we take action to modify problems--geoengineering