Where have all the good trees gone?

Extent of Deforestation in the Amazon

Consider this gif:

Figure 1: A gif showing deforestation in the Amazon Rainforest (Source: Giphy, accessed 29/11/2017)

You might remember it from an earlier blog post. It shows how much of the Amazon Rainforest has been removed since the year 2000, i.e. the extent of deforestation in the Amazon. Without any political borders drawn on, I'm not precisely sure which parts of the Amazon are shown exactly. Thankfully, a number of scientists have conducted research precisely into this because of the potential threat such deforestation poses to ecosystem services provided by the Amazon; threats that subsequent posts will detail.

A very nice table of deforestation in the Brazilian Amazon can be found here, based on estimates from the Brazilian National Institute of Space Research and the United Nations Food and Agricultural Organisation. It includes tree cover loss in Brazil beginning from the 1970s, which is particularly important considering that the Brazilian Amazon makes up 60% of the total rainforest. The amount of forest lost annually increased significantly in the 1970s and 1980s from pre-1970s levels, but has begun to slow since then. Although, there are peaks in 1995 and 2004, at which times annual deforestation rates were unsteady.

Rates of forest loss have slowly been declining since then. But remember, considering that full tree regrowth in the Brazilian Amazon is a process that occurs on the scale of hundreds of years (Houghton et al., 2000), deforestation since the 1970s has been largely cumulative. So even though rates of deforestation have been decreasing in the past decade, the total forest lost has continued to increase. Today, only 81% of the pre-1970 Brazilian Amazon forest cover has been retained, compared to 97.6% retained in the 1970s, relating to a 768,935 square kilometer and 98,400 square kilometer loss respectively since 1970. As you can tell, a staggering amount of the Brazilian Amazon has been lost.

As for elsewhere in the Amazon, it's all very concerning as well. To put this into perspective, a high-resolution study of global forest cover in the 21st century by Hansen et al. (2013) estimated that the rate of loss of forest land cover in the Amazon between 2000 and 2012 was, in the words of The Guardian, in the order of magnitude of 50 football pitches a minute, and with a total loss 10 times greater than the size of the UK. Equally concerning, although not directly related, Hansen et al. estimated that global forest loss was 2.3 million square kilometers in the same time period, with only 0.8 million square kilometers afforested. In comparison, the Amazon only had a third of what was deforested replaced.

In the true spirit of science, a number of figures have been created to represent this beautifully.

Figure 2: Tree cover loss across various countries containing parts of the Amazon Rainforest. (Source: Butler, 2017, updated)

Figure 2 from Butler (2017, updated), based on 2017 data from a group of researchers led by Matt Hansen (yes, the very same as the one referenced above!) at the University of Maryland, shows Amazonian forest loss in hectares per year across various regions between 2001 and 2015. Brazil is far and away the winner, or loser, depending on how you look at it. So much so that it's difficult to see the disparity between other countries. It's a good indication of the sheer amount of forest loss occurring in Brazil.

Figure 3: Tree cover loss across various countries containing parts of the Amazon Rainforest, without Brazil. (Source: Butler, 2017, updated)

Figure 3 depicts forest loss across regions without Brazil. It's easier to see the disparity between other countries here, with Bolivia, Peru, and Colombia seeing the greatest deforestation across the whole period. Encouragingly, deforestation in the Amazon seems to be declining across the most significant regions. Finally, some hope!

The disparity between Brazil and the other countries is clear, but don't be fooled by pretty graphs, dear reader(s)! This doesn't necessarily mean that the rate or proportion of loss in Brazil is greater than other nations. Remember, it's thought that Brazil contains about 60% of the Amazon Rainforest within its borders. It's entirely possible that Brazil's greater total forest loss is due to solely to its greater area, although it's difficult to tell without the data. Regardless, the sheer extent of deforestation occurring in the Amazon is alarming, and is clearly evident.

That's all for this post, folks, but I've got another one in the works, a Deforestation: Part 2, if you will. It should be up very soon so stay tuned!