All CO2-spewing kit now in existence is OK for the planet
That V8 Jag? Run it 'til it wears out, you're OK
All the carbon-spewing machinery the human race now possesses - powerplants, transportation, boilers, the lot - can be kept running for its entire designed life without any significant ill effects on the planetary ecosystem, according to new analysis. It is the new machinery to replace what we now have which will either push atmospheric carbon over the UN's red line - or not.
Chuck some more coal in the Aga - but you can't have a new one when it wears out
The new boffinry comes from Steven Davis and Ken Caldeira of the Carnegie Institution. They've worked out how long all the current cars, trucks, buses, ships, airliners, coal-fired power stations, combi boilers etc will last before needing to be replaced and totted up all the resulting atmospheric carbon.
As the graph shows, all of the gear now existing can be run until it wears out, and CO2 will stay well below 450 parts per million (ppm) - the amount that the UN says we must stay below in order to avoid damaging levels of global warming.
Obviously if we only did that, we'd soon have fewer and fewer working power stations, vehicles, farms, lights etc and human civilisation would start going to the dogs*. So the likelihood is that in fact all this stuff will be replaced - and more than replaced. But it will be the carbon emissions of the replacements which bust - or fail to bust - the 450 ppm line. The game is still all to play for.
"The answer surprised us," says Davis. "Going into this study, we thought that existing sources of CO2 emissions would be enough to push us beyond 450 ppm and 2°C warming."
"Because most of the threat from climate change will come from energy infrastructure we have yet to build, it is critically important that we build the right stuff now – that is, low carbon emission energy technologies," says Caldeira.
"We cannot be complacent just because we haven't yet reached a point of no return."
The two men's analysis won't be welcome in some quarters. For instance, famous carbopocalypse prophet James Hansen of NASA says that  actually any carbon rise above 350 ppm, and we're toast.
The new research is to be published in Science, the boffin's boffinry mag. ®
*Obviously there are many who would say this isn't true: debate the feasibility and desirability of trying to sustain the modern human population without energy-intensive technologies - or alternatively the idea of reducing its numbers massively in a short space of time - among yourselves.