I’ve Looked At Clouds From Both Sides Now

The Practice of Life On Earth

Dawn Clouds Photo by Martha Ture

The noise to signal ratio is pretty unpleasant these days. There are opinions and facts, as numerous and invasive as ants in the kitchen. We don’t see a lot of coverage of the mortal issue of climate, though.

It’s curious. Mainstream, social, and independent media are largely ignoring the fate of our life support, in favor of covering political turmoil at home and abroad, the sins and crimes of the Trumpiosi and policy proposals, the fate and future of Syria, Ukraine, Hezbollah, Israel, the myriad matters of sports, culture, TikTok, housing, homelessness, and the most recent AI advances.

It seems irrational.

But this week in Washington, D.C., the annual meeting of the American Geophysical Union did the heavy lifting and addressed the question of why the planet Earth is so hot, hotter than the climate scientists forecast or expected, inexplicably hotter.

This year is “virtually certain” to end up as the hottest on record, according to the European climate monitor., as reported in Copernicus, and the first year in which air temperature passed 1.5 C above pre-industrial levels.

Raymond Zhong at the New York Times has written a clear, informative article covering the meeting and summarizing the discussion of global temperature rise and possible causes. In summary, there is no clear answer as to cause. One possible explanation was proposed by a European team – a decrease in planetary cloud cover.

Their Science article abstract points out that human-caused warming and El Nino don’t account for 0.2K of the temperature increase. The problem appears to be low cloud cover in the northern and tropical latitudes.

“Utilizing satellite and reanalysis data, we identify a record-low planetary albedo as the primary factor bridging this gap. The decline is apparently caused largely by a reduced low-cloud cover in the northern mid-latitudes and tropics, in continuation of a multi-annual trend. Further exploring the low-cloud trend and understanding how much of it is due to internal variability, reduced aerosol concentrations, or a possibly emerging low-cloud feedback will be crucial for assessing the current and expected future warming.”

Why the loss of cloud cover? So far, no clear answer has been put forward, but Robert Rohde, chief scientist at Berkeley Earth, named some possible causal factors. They are decreases in sulfur pollution and in Saharan dust in the atmosphere.

Wait.

So a reduction in sulfur pollution leads to less cloud cover. And a reduction in Saharan dust leads to less cloud cover. We can see how fewer aerosols in the atmosphere would reduce cloud cover, but didn’t we seek to reduce airborne sulfur pollution and Saharan dust? Is this a case of damned if you do and damned if you don’t?

In fact, the particulates, nitrogen oxides, and sulfur oxides – ROX, NOX, and SOX to air pollution wonks – those air pollutants produced by burning fossil fuels, can

have a cooling effect as they block and scatter sunlight and stimulate cloud formation.

So yes. We are damned if we do and damned if we don’t. At least so far.

And if the source of sulfur pollution is the burning of fossil fuels, then logically, we have to say that part of the source of the missing 0.2 K of temperature increase in the rapid warming of Earth is, in fact, human-caused. Those sulfur particles are anthropogenic as hell.

And so is the Saharan dust. In a 2021 study, NASA forecast a more substantial reduction in dust activity, based on anticipated climate warming.

So what can we do to restore the clouds to save ourselves? Other sources of cloud cover exist besides sulfur pollution and Saharan dust. Oceans, lakes, rivers are primary sources of water vapor. Forests also roduce aerosols- monoterpenes, isoprenes and sesquiterpenes - that help form cloud seeds.

We could do worse than reversing some of the deforestation resulting from wars, droughts, and wildfires. The United Nations Framework convention on Climate Change uses forest estimates to calculate land use carbon emissions. Since the burning of Canada’s boreal forests, the amount of carbon sequestration has dropped. Extreme fires like last year’s that ravage enormous tracts of forests are “completely absent from the current climate models,” said Philippe Ciais, a researcher at the Laboratory of Climate and Environmental Sciences, near Paris, who tracks carbon dioxide emissions.

Because of that, he said, “the models are probably too optimistic.”

Canada has begun a 2 billion trees reforestation project. Led by the Canadian Forest Service, up to $3.2 billion will be invested in tree planting efforts across Canada. The funding will be used to support provinces, territories, third-party organizations (including for-profit and not-for profit) and Indigenous organizations in meeting the target. The project is part of Canada’s approach to climate change and biodiversity loss.

If we can restore a measurable amount of cloud cover within the coming decade, we may be able to drop more than 0.2K from global warming.