Bolsonaro thinks ‘reforesting Europe’ can offset the damage he is doing to the Amazon. He is so very wrong

I’m an expert on climate change. The Brazilian president has next to no idea what he’s talking about

If the Amazon rainforest goes up in smoke, then we will all be cooked. Its two million square miles hold over a hundred billion tons of carbon. At a time when we urgently need to reduce carbon emissions, the current fires that are raging across the region are an international disaster and a source of increasing alarm.

Some of this alarm has translated into offers of cash to help fight these fires with the G7 pledging $20m. While better than nothing, these sums of money are tiny when compared to the billions splashed out on another seismic event of recent times: the bailing out of the banks. So, given that most of the fires are burning through Brazilian forests and thus it is Brazil that needs to shoulder the greatest burden when it comes to tackling them, it is not surprising that its president Jair Bolsonaro was not overcome with gratitude.

But rather than asking for more, Bolsanaro initially told the G7 it can keep its money. He also suggested that these funds could be used to plant more trees in Europe and jibed that the history of colonialism still casts a long shadow over the region, with European nations such as France still attempting to meddle in Brazilian affairs.

After all that, it now appears Bolsanaro will accept the G7 money if the French president Emmanuel Macron apologises to Bolsanaro for saying mean things about him. Which appear to have been said as a consequence of Bolsanaro saying mean things about Macron’s wife. All very grown up behaviour when we’re staring down the barrel of a climate emergency.

It’s tempting to view such exchanges via the grotesquely distorting lens of post-Trump international relations in which insults and vulgarities are the norm, and relationships between countries are not much more dignified than playground squabbles. But there is a much more important story here.

While I doubt it was a serious suggestion, the idea that the loss of trees in the Amazon could be offset by planting trees in Europe is misguided. The slashing and burning of forests liberates carbon instantly, where it will stay in the atmosphere for centuries. It will take many years if not decades for trees planted in France to fully offset the carbon liberated over the past few weeks.

Furthermore, it may even be the case that some tree planting could actually increase global warming. This would come as a result in changes in land cover and the atmospheric effects forests produce.

A forest canopy is typically darker than bare ground or grassland. Darker objects will absorb more energy from the sun than lighter, more reflective objects. What this means is that reforesting bare ground can lead to a decrease in the reflectivity of that area of land, and so less energy is reflected back out into space which means more is absorbed, increasing the surface temperature. You may ask: but on a hot, sunny day, isn’t a forest a cool and pleasant place when compared to a bare field? Yes, the forest floor is. But the forest canopy is not.

More complications arise from the mix of gasses that trees emit as they grow. Some of these help form reflective clouds and so will reduce warming. But some can produce gasses that have an overall warming effect.

This doesn’t mean that tree planting cannot have a very important positive contribution to help us avoid dangerous climate change. But it does mean that it makes absolutely no sense to spend money to plant trees in the northern hemisphere to attempt to offset the carbon released when mature ones near the equator are burnt.

The question that really needs to be asked, is why are these fires burning at record rates? It’s no secret that Bolsanaro has powerful connections to organisations that seek to replace rainforests with cattle ranches or mines. Consequently, it may suit his purposes that thousands of square miles of forest are being cleared.

But his statement about colonialism is well taken because it is the developed world that has pushed the climate into a state where it cannot afford the release of Amazon rainforest carbon. The message of “we rich nations got here first so you are going to have to slow down the exploitation of your natural resources” will resonate with and aggravate many people beyond Bolsanaro and his government.

All of humanity benefits from a stable climate. Yet still a tiny minority carry on without regard, profiting from the destruction of much of the Amazon rainforest. The current spat between Brazil and France demonstrates how dysfunctional our current politics is when it comes to what is perhaps the greatest challenge humanity has ever faced.

Bolsanaro and Macron both need to cool it and focus on the bigger issues. Further delay risks future arguments being over nothing but embers.