杏吧原创

It鈥檚 that time of year, at least in the northern hemisphere, when people start to plan their summer holidays. I am in the market myself, hoping to take my sons to Mexico in July. We will fly, of course. I know I am a hypocrite for preaching a green lifestyle while participating in one of the most climate-damaging activities available. I always buy the carbon offset option, but have a lingering feeling I am being greenwashed. Now I have looked into it, I think that feeling is correct.

The last flight I took, I paid an extra $27.84 on a 拢1703.09 ($2137.21) ticket that took me 34,000 kilometres on a circuitous route from London to Tahiti and back. The certificate I got from the offsetting company says that I offset 1.69 鈥渕t鈥� of carbon. I am guessing that means metric tonnes rather than megatonnes. If so, it is nowhere near enough. According to an I later ran this through, I emitted more than 6 tonnes of carbon dioxide as a result of my flight. That alone busts my , which should be no more than 2.5 tonnes a year.

I also have no idea whether that payment actually compensated for a portion of my emissions. What I assume is that the money 鈥� at least some of it 鈥� was invested in a voluntary carbon market, which is the only kind available. These allow individuals and companies to offset their emissions by investing money in nature-based solutions, such as planting forests, or in projects that prevent carbon being emitted in the first place. Voluntary carbon markets are the best thing we have at the moment, but are hugely flawed.

Leaving aside whether offsetting compensates for my emissions, there are transparency issues. I don鈥檛 know what my $27.84 was invested in 鈥� the certificate says it was 鈥渄istributed across our projects鈥�. These include tree planting, renewable energy projects and 鈥渁voided nature loss鈥�, which means preventing carbon emissions by not cutting down trees or changing natural habitat into farmland. The company鈥檚 website tells me 90 per cent of my $27.84 went directly to one or more of these voluntary projects.

I have no reason to disbelieve the company鈥檚 claim that they invested roughly $25 to support one or more of these laudable schemes. But according to Kaya Axelsson of the Oxford Net Zero project, there is a general problem in this area. 鈥淐arbon credits are generally invisible, it鈥檚 hard for buyers to easily discern quality,鈥� she says. That is in part because the market is unregulated and lacks robust consumer protection.

The offset market is a drop in the ocean of what is needed and a distraction from the true solution: decarbonisation

One of the major grey areas is permanence. Carbon offsetting only works if it keeps carbon out of the atmosphere on the timescale that it lingers, which is thousands of years. Projects that involve planting trees can鈥檛 promise this. They may work in the short term, but the carbon will eventually go back into the atmosphere.

The only offsetting worth its salt is that which permanently sequesters carbon in geological storage, says Myles Allen at the University of Oxford. But very few, if any, schemes offer this. In fact, he says, only 5 per cent offer carbon removal at all rather than avoided emissions, and they all invest in short-term solutions.

This opens the door to the second big problem: additionality. How do we know the offset wouldn鈥檛 have happened anyway? The industry routinely in a vice called double-counting, in which offsets are sold for projects that have already been announced and factored into somebody else鈥檚 net-zero commitments. If that is the case, an investment is worthless.

The third big problem is scale. Right now, human activity emits 100 million tonnes of carbon a day, according to Injy Johnstone at the University of Oxford, an author of the world-leading . Offsetting removes just 5.5 per cent of that, she says, and the prospect for closing the gap is minimal.

All told, the offset market is a drop in the ocean of what is needed and a distraction from the true solution: decarbonisation. It also perpetuates our mass addiction to consumerism. Axelsson likens it to the medieval Catholic system of indulgences, where worried believers did good works to reduce the punishments they would endure in the afterlife.

I don鈥檛 like to think of myself as a consumer of indulgences, but I have come to believe my offsetting is exactly that. Mexico may be the last long-haul flight I take, at least until offsetting is put on a more scientific and credible footing.

It鈥檚 not too late to do that, but serious reform and oversight is needed. Offsetting can, when done well, play a vital role in achieving net zero, says Johnstone. 鈥淲e urgently need climate mitigation, and offsetting strategies are one key lever we have to do so,鈥� she says. But when you click the button on an 鈥渙ffset鈥� for your flights, be aware that you are probably being had.