Archive by category | Atmospheric Science

The real holes in climate science

When I started working last month on a news feature about gaps in climate science I was expecting a tough reporting job. Too fresh, so I thought, were the scars the field and many leading scientists had received from the hacking affair at the Climate Research Unit (CRU) in Norwich to readily discuss with a reporter the ‘dirty laundry’ (my phrase) of climate science.  Read more

Sunburnt Southern Hemisphere in 2095

Sunburnt Southern Hemisphere in 2095

Global warming doesn’t just change the weather, it also affects the ozone layer. According to a detailed new modelling study, by 2095 the springtime UV index (UVI) could go up by as much as 20% on the southernmost section of the planet, as altered atmospheric circulation pushes more stratospheric ozone into the Northern Hemisphere. That’s nearly half the UVI increase caused by ozone-eating pollutants in the late twentieth century – but coming from climate change alone.  Read more

Ozone: The patient is not getting sicker

Ozone: The patient is not getting sicker

Twenty years after the Montreal Protocol came into effect to regulate substances that deplete the ozone layer, the annual ozone hole above Antarctica shows no signs of recovery. A feature article and editorial in Nature today explain why this is so, and why the Montreal Protocol has been a unique success nonetheless. As things stand, scientists expect the first signs of recovery of springtime ozone depletion in the polar stratosphere around the year 2065. Outside polar regions, where chemical ozone destruction is less pronounced but potentially harmful to human health, it appears as if ozone levels are beginning to increase.  Read more

Cloud shields breached by warming

Cloud shields breached by warming

Blankets of low clouds shield and cool the Earth’s surface – but in a warming climate, will this safety blanket thicken, or will it deteriorate? That question has bugged climatologists for decades. A paper published in Science today (subscription) now offers convincing evidence that warming leads to fewer clouds, and thus exposure to more warming.  Read more

Untangling aerosol effects

When it comes to describing how human activities are altering the Earth’s climate, aerosol emissions can tie your tongue in knots. Airborne pollution particles grouped under the “aerosol” heading come in a wide assortment – and some, as this NRCC article explains, tend to absorb sunlight and heat up the atmosphere, while others are more reflective and cooling. On top of that, it’s been thought to make a difference whether this potpourri of pollutants ends up drifting in clear skies or above clouds. Coming in now are the first experimental data that show just how important the effect of cloudiness is.  Read more

Biomass, biomass, burning black

Biomass, biomass, burning black

A study published in Science today (subscription) uses carbon-14 measurements to figure out where the black carbon drifting in the haze above South Asia is coming from. That’s a prerequisite to cleaning it up – which, as we’ve reported here, could be a major boon to a very vulnerable region. The light-absorbing compound not only causes cancer (among other ill health effects), but reportedly warms some places as much as greenhouse gases do. Because its lifespan in the atmosphere is far shorter than carbon dioxide’s, these impacts could potentially be reduced quickly – if we knew where to clamp down.  Read more