Dams are often talked about as a fantastic way to cut carbon emissions. Aside from the fact that many dams in the world are more like a battery (water is pumped up when electricity is cheap and then flows down when it is expensive creating electricity) dams built in rainforests have such a huge initial carbon footprint from the destruction of the rainforest that sat on the land that in some cases the carbon savings will never make up for the carbon loss.
I am not saying that dams are useless. Far from it. However, if your dam is there to cut carbon emissions, it is in the wrong place.
Brazil has gone into dams in a large way. Unfortunately, these are so poorly constructed that they are collapsing. This means that land downstream gets hit twice – firstly loosing most of their water supply as the dam fills and then again as they are deluged with months or years of water in one go. What is worse here, is that many dams here are holding back toxic mud, left over after mining work. As such even after the flood of water has gone down, much of the land it has touched will be less productive.
It is not an either or choice for countries like brazil. They aim to cut carbon emissions by 45% by 2030, however 28-33% of that will come from non-hydropower sources (70%). Indeed in Brazil wind power is generating increasing amounts of their power. Indeed, in terms of installed wind power, Brazil now ranks just 8th in the world. Also given it is a country lying in the tropics, it gets a great deal of sun – there are currently 8.5GW of solar installed meeting 1.5% of Brazils needs. However 3.4GW were added just in 2020. It is therefore highly likely that assuming this acceleration continues perhaps 20% of Brazils electricity needs could come from solar by this date.
We need to cut our emissions dramatically in the next 10 years, however political pressure is often meaning that these efforts are going in the wrong direction.