The State of Our Climate 
NOAA GHG
monitoring

​data visualization​
NASA Earth Observation
​global maps  ​
Atmospheric 
greenhouse gases
​​ 2016

 CO2    404 ppm
​ CH4  1854 ppb
​ N2O    329 pp
b
Atmospheric CO2 ​15 million year high​
Univ. Bremen
Arctic sea ice
SPEI ​
Global drought
The State of the Climate (BAMS)
 Bulletin American      Meteorological Society 


WMO 2015 Alarming
​ State of 2015 Climate 
short PPt
Image​
March 2016 PDF
James Hansen 2015
​2014 record

CO2 Now ​
Today's satellite 
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Univ Califrnia Irvine
Site maintained by Peter Carter

NOAA AGGGI Greenhouse Gas
I​ndex (Annual Radiative
​heat ​forcing. Best single
climate change indicator 
Stratospheric Ozone Depletion 
The 'hole' in the ozone layer​
xt.
This year 2021, NASA satellite observations determined the ozone hole reached a maximum of 9.6 million square miles (24.8 million square kilometers) – roughly the size of North America – before beginning to shrink in mid-October. Colder-than-average temperatures and strong winds in the stratosphere circling Antarctica contributed to the hole’s size.
What we call the ozone hole is a thinning of the protective ozone layer in the stratosphere (the upper layer of Earth’s atmosphere) above Antarctica that begins every September. Chlorine and bromine derived from human-produced compounds are released from reactions on high-altitude polar clouds. The chemical reactions then begin to destroy the ozone layer as the sun rises in the Antarctic at the end of winter. 
The stratospheric ozone layer is a natural layer of gas in the upper atmosphere that protects humans and other living things from harmful ultraviolet (UV) radiation from the sun.
Although ozone is present in small concentrations throughout the atmosphere, most (around 90%) exists in the stratosphere, a layer 10 to 50 kilometres above the Earth’s surface. The ozone layer filters out most of the sun's harmful UV radiation and is therefore crucial to life on Earth.
Ozone depletion
Scientists discovered in the 1970s that the ozone layer was being depleted.
Atmospheric concentrations of ozone vary naturally depending on temperature, weather, latitude and altitude, while substances ejected by natural events such as volcanic eruptions can also affect ozone levels.
However, these natural phenomena could not explain the levels of depletion observed and scientific evidence revealed that certain man-made chemicals were the cause. These ozone-depleting substances were mostly introduced in the 1970s in a wide range of industrial and consumer applications, mainly refrigerators, air conditioners and fire extinguishers.


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Stratospheric ozone depletion and global climate change 

​The most obvious linkage between efforts to mitigate ozone depletion and climate change is the fact that certain ozone-depleting substances (ODS) such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are also powerful greenhouse gases.
In addition, hydrofluorocarbons (HFCs) and other halocarbons, which do not deplete the ozone layer but are greenhouse gases, are currently the commonly used as alternatives to CFCs and HCFCs. 

Another important linkage involves the way that ozone-depleting substances and greenhouse gases alter certain processes in the atmosphere so as to enhance both global warming and stratospheric ozone depletion. These changes result in a warming of the troposphere (lower atmosphere) and a cooling of the stratosphere. Stratospheric cooling is a key factor in the development of ozone holes over the poles.
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