Our planet's air has cleared up in the past decade or two, allowing more sunshine to reach the ground, say two studies in Science this week.
Reductions in industrial emissions in many countries, along with the use of particulate filters for car exhausts and smoke stacks, seem to have reduced the amount of dirt in the atmosphere and made the sky more transparent.
That sounds like very good news. But the researchers say that more solar energy arriving on the ground will also make the surface warmer, and this may add to the problems of global warming. More sunlight will also have knock-on effects on cloud cover, winds, rainfall and air temperature that are difficult to predict.
Note the last sentence. I've been saying all of this is so difficult to predict that perhaps the dire predictions of the "global warming" crowd aren't as scientifically valid as some would like to claim they are. This is just another in a long line of indicators that I'm probably right.
It is fairly ironic though that cleaning up our air is now seen as a problem.
UPDATE: Commenter "anondebus" reminds us that just a recently as January of this year, scientists were convinced we had exactly the opposite problem:
We are all seeing rather less of the Sun, according to scientists who have been looking at five decades of sunlight measurements.
They have reached the disturbing conclusion that the amount of solar energy reaching the Earth's surface has been gradually falling.
Paradoxically, the decline in sunlight may mean that global warming is a far greater threat to society than previously thought.
Dr Stanhill called it "global dimming", but his research, published in 2001, met a sceptical response from other scientists.
It was only recently, when his conclusions were confirmed by Australian scientists using a completely different method to estimate solar radiation, that climate scientists at last woke up to the reality of global dimming.
Dimming appears to be caused by air pollution.
When you cannot even agree on how much sunlight we are getting, which is of course the engine driving our climate, it seems a little dubious to be making a whole lot of other claims about climatology. (But dubious claims can bring in the research money. Ca-Ching!)
To claim that you know what is driving climate change at this point in time is akin to the alchemist claiming he knows how to make gold; it is simple nonsense. Now, it needn't always be nonsense (as the poor alchemist is forever doomed), but at present there is no other way to view it.