CO2 Reaches Tipping Point!
By Paul Homewood
We’re all going to die! From the Mail:
6 June may sound like an insignificant date to many, but it could mark a ‘tipping point’ in the world’s history, an expert has warned.
An atmospheric measuring station at Cape Grim in Tasmania is expected to record a carbon dioxide (CO2) concentration of 400 parts per million (ppm) on or around this day – a significant number marking a climate change milestone.
While 400ppm has been recorded before, the Tasmanian location is regarded as one of the cleanest air sources in the world, so such levels of pollution are said to be a real blow.
The measure is an indicator of the amount of planet-warming gases being pumped into the atmosphere at record rates and the concentrations are the highest in millions of years.
The measurements of 400ppm come almost three decades after what is considered the ‘safe’ level of 350ppm was passed.
‘Once it reaches 400ppm at Cape Grim it’s very unlikely to drop below 400 again,’ Dr Paul Fraser, a Fellow at the Commonwealth Scientific and Industrial Research Organisation (Csiro) told Ninemsn.
While the difference of 0.1ppm may seem trivial, the expert said it marks a ‘psychological tipping point’ in our battle against global warming.
There is more drivel along these lines, but I was struck by this comment:
Experts worry that when 400ppm becomes the norm, polluted and densely populated cities such as Beijing could record carbon figures as high as 700ppm, bring a lot of health concerns.
Currently, the air surrounding a congested road is probably around 500ppm.
Accompanied by this highly misleading photo, which attempts to conflate CO2 with smog:
Experts worry that when 400ppm becomes the norm, polluted and densely populated cities such as Beijing (stock image) could record carbon figures as high as 700ppm, bring a lot of health concerns
I am certainly not aware of any evidence that CO2 is any way harmful in to humans at these sort of levels.
Obviously as CO2 is heavier than air, it can sink to the ground in confined spaces and lead to asphyxiation. But according to the Health & Safety Executive, CO2 is naturally present in the air we breathe at a concentration of about 0.037% and is not harmful to health at low concentrations.
They go on to say:
In GB, CO2 is classed as a ‘substance hazardous to health’ under the Control of Substances Hazardous to Health Regulations 2002 (COSHH). The HSE publication ‘EH40/2005 Workplace exposure limits’ provides workplace exposure limits (WELs) for CO2. WELs are limits to airborne concentrations of hazardous substances in the workplace and are set in order to help protect the health of workers. Workplace exposure is calculated by taking an average over a specified period of time. The WELs for CO2 are:
- Long-term exposure limit (8-hr reference period) of 5000 ppm
- Short-term exposure limit (15 minute reference period) of 15000 ppm
As with all HSE recommendations, they are doubtlessly well below realistic safe limits.
There is also plenty of evidence that CO2 has many beneficial effects for the human body. According to the Normalbreathing website, having a normal level of CO2 in the lungs and arterial blood (40 mm Hg or about 5.3% at sea level) is imperative for normal health.
Obviously most of this CO2 is that produced during respiration. Their view, however, is that many people actually hyperventilate, which leads to there being too little CO2 in the lungs.
Either way, it is not clear why 700ppm should be in any way harmful. This all seems just a cheap attempt to reinforce the message that CO2 is dangerous pollution.