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I thought the Cloud Question was still unresolved? More water vapour = more clouds. Clouds are highly reflective, so reflect much of the incoming solar energy

I thought the Cloud Question was still unresolved? More water vapour = more clouds. Clouds are highly reflective, so reflect much of the incoming solar energy away. Last I heard, the net effect of More Greenhouse vs Higher Albedo wasn't worked out. Has this changed?

pfdietz 4y ago
The clouds of Venus reflect most of the sunlight hitting the planet. The 1% that reaches the surface is still enough to keep that surface hot enough to melt lead.
modo_mario 4y ago
Will we get a much stronger Albedo effect considering all the ice that's melting?
- marcus_holmes 4y ago
  ice only appears at the poles and mountainous regions. the poles are negligable for albedo becuase so little solar radiation reaches them. And the glaciers as a percentage of global area are negligable (glaciers are a minor % of land, and land is only 25% of global area. Clouds cover the oceans).
  - modo_mario 4y ago
    Someone else in this thread thought differently saying : "It's gotten brighter over even just the last 20 million years. The ice caps helped reflect nearly .39 of it, but soot and melting are lowering that. It's called albedo and that loss will dwarf the CO2 Heat trapping." Similarly I found that in the geologically recent past, the ice–albedo positive feedback has played a major role in the advances and retreats of the Pleistocene (~2.6 Ma to ~10 ka ago) ice sheets and that the ice at the arctic is in fact not that negligible given the loss of it in relation to the much higher warming at the poles. To what extent do you believe clouds contribute?
    - marcus_holmes 4y ago
      Over a timescale of 20 million years there'll be Ice Ages when a significant portion of the planet is covered in ice, so I can see how that will affect albedo then. As I understand it, the extent of cloud cover affecting the planet's albedo (and whether that offsets the warming from the greenhouse effect from water vapour) is still an open question in meteorology. I'm absolutely not an expert on any of this - I was genuinely asking the question out of interest.

pfdietz 4y ago

The clouds of Venus reflect most of the sunlight hitting the planet. The 1% that reaches the surface is still enough to keep that surface hot enough to melt lead.

modo_mario 4y ago

Will we get a much stronger Albedo effect considering all the ice that's melting?

marcus_holmes 4y ago
ice only appears at the poles and mountainous regions. the poles are negligable for albedo becuase so little solar radiation reaches them. And the glaciers as a percentage of global area are negligable (glaciers are a minor % of land, and land is only 25% of global area. Clouds cover the oceans).
- modo_mario 4y ago
  Someone else in this thread thought differently saying : "It's gotten brighter over even just the last 20 million years. The ice caps helped reflect nearly .39 of it, but soot and melting are lowering that. It's called albedo and that loss will dwarf the CO2 Heat trapping." Similarly I found that in the geologically recent past, the ice–albedo positive feedback has played a major role in the advances and retreats of the Pleistocene (~2.6 Ma to ~10 ka ago) ice sheets and that the ice at the arctic is in fact not that negligible given the loss of it in relation to the much higher warming at the poles. To what extent do you believe clouds contribute?
  - marcus_holmes 4y ago
    Over a timescale of 20 million years there'll be Ice Ages when a significant portion of the planet is covered in ice, so I can see how that will affect albedo then. As I understand it, the extent of cloud cover affecting the planet's albedo (and whether that offsets the warming from the greenhouse effect from water vapour) is still an open question in meteorology. I'm absolutely not an expert on any of this - I was genuinely asking the question out of interest.