I went to a talk at COP22 in Marrakesh about the challenges of achieving the headline target of the Paris Agreement and the technologies needed to get there, and thought it was so interesting, I really wanted to share it, so all credit to the speakers, as below.

Young people supported the Climate Vulnerable Forum in calling for the more ambitious target of a maximum of 1.5 degrees global average warming to be included in the Paris Agreement, and it’s in! But now it’s there, we need to decide how we’re going to get there. A lot of the current models are based on technologies that don’t exist. The two main options of geo-engineering (definition = large scale (planetary), intentional, human interaction with nature, to improve climate) are CO2 removal and solar radiation management technologies…


C02 Removal

As carbon dioxide (CO2) is the primary greenhouse gas emitted by human activity into the atmosphere, it would make sense just to take it out again right? Sadly it’s not that easy. CO2 removal mimics nature e.g. growing lots more trees, direct air capture, chemical means of removing CO2, but is generally very expensive, possibly more expensive than mitigation (just reducing the CO2 input into the atmosphere in the first place) and takes a long time.

BECCS (Bio-energy with Carbon Capture and Storage), combining planting lots of trees/biomass with capturing that carbon and geologically storing it, is most often talked about, because it looks nice and easy, but it’s just not at this scale. There would be massive impacts on landuse, biodiversity, water and more which would actually have much worse environmental impacts than warming to 2 degrees!! Also, who’s land would be used? Land is cheaper in the global south, so the obvious choice would be to use land there. But Land rights are critically important for resilience, adaptation, security, food.

One of the many invisible assumptions in the models to keep under 1.5 is that between 500m – 3bn Ha of land would be needed/used for bioenergy (that’s about the size of India), but 1.5Bn is currently used for crops. And these huge figures are simply not achievable from a social point of view. It would be severely affecting the most vulnerable and without a voice, the ones the 1.5 degree target is supposed to protect!The technology is also restricted as there is limited capacity to store carbon from BECCS – usually in places where oil has been extracted – but there are not a lot of places where this is viable. Assumptions about BECCS are driving low ambition now. Consumption and economic models need to change. We need to name it as a problem.

Photosynthesis is currently the only tech we have to suck CO2 from the air. Grow, suck carbon, burn it, store it underground. These are the very dangerous assumptions allowing Governments and the fossil fuel industry to carry on as normal, thinking everything will be OK. We can’t set targets thinking the technology will come along later but not take the action required now. 

Solar Radiation Management

Solar radiation management involves the injection of aerosols into the atmosphere to help deflect the warming rays of the sun, mimicking volcanoes which emit lots of sulphur into the atmosphere and you can see the temperatures visibly decline. However this doesn’t solve the problem at all, as the CO2 is still there, but does cool down the planet; it’s predicted to be relatively cheap by the time we need it (although this in itself is a massive assumption!) and takes effect pretty quickly.

Solar radiation management would lead to reduced precipitation, and reduced sunlight and possibly ozone depletion. We would only do this in a couple of decades time when the world has already warmed, so we’d also have those impacts to take into account.

There is currently no clear public policy guidance to even do research on solar radiation. And who decides to use it, on behalf of whom? A country could just decide to do it one day. Then how far do you cool down? It could have huge impacts on the world. And we’d still need mitigation, because not we’ve still not solved the problem so we’d have to do it continuously for years. And what if it breaks one day? The tech is relatively simple, but the questions remain – when to start, when to stop, how much for, who decides and who governs? It sounds to me like it would be much simpler to solve the problem in the first place. Prevention is better than cure complicated patch up afterwards.


Most discussions are focusing on post-2020 and the Paris Agreement, when the most critical years are before that, when these technologies are not available. Analysis of the IPCC data reveals we only have 5 years left of the global carbon budget if we want a high probability of staying under 1.5 degrees! We are neglecting knowledge of the solutions available now! We know who the high emitters are – 10% of the world’s population are responsible for 45% of the emissions. Only 7% of people fly globally. But we’re not designing climate policies to target these high emitters.  We know we need to stop new fossil fuels – we need to shut down current reserves and keep 80% of known fossil fuels in the ground, let alone stop finding new ones. There are other sectors as well, like waste. For example if the EU were to implement a circular economy, this could save equivalent emissions from Netherlands! Transport – represents almost a quarter of Europe’s greenhouse gas emissions and is the main cause of air pollution in cities, and we need to rapidly increase the efficiency of transport networks and make a widescale move to zero-emissions vehicles. Forest & land sector – key for successive emissions to be sequestered, although there are better and worse ways of doing it. Natural ecosystem restoration efforts as a one time thing (not repeatedly) can sequester really large amounts of carbon – to be debated and need to discuss the role agriculture can play – ways not to violate human rights etc. But no-one’s talking about these, we’re talking about crazy solutions that don’t exist! We have the real solutions, we just need to do them, NOW.