There Goes the Neighborhood...
...and we're the ones who ruined it. Climate change.
97% of scientists are in agreement. We all know it’s real. We know about the threats it presents. We know about our own contributions to global warming. Thankfully, it has been getting more and more coverage in the media (although who knows how much it will be covered in the future).
But how do you explain to grandpa, your cousins, your friends, or even strangers on the internet, the gravity of climate change? That it not only affects the flowers grown for you to get on Valentine's Day but the bees that pollinate them, too? That it affects the coffee they drink? How do you explain that climate change is serious and causes extinctions of species after loss of habitats, ocean acidification, and forest fragmentation? If only there were a way...
Why not bring the effects of climate change on our closest living relatives to their attention?
“Strong influence of palaeoclimate on the structure of modern African mammal communities”, a study from October 2016, can help. The study looked at how mammal communities are influenced by current modern climate in comparison to past climates from the mid-Holocene (about 6,000 years ago) and the Last Glacial Maximum (about 22,000 years ago). Data came from Africa; the continent least affected by late Quaternary extinction events—events that include the extinction of giant lemurs in Madagascar as well as wooly mammoths and cave bears in Europe—with most large mammals going extinct except for those in Africa. For this study, 203 species of African mammals were subdivided into three groups: carnivorans (lions, hyenas), ungulates (think zebras, wildebeest), and primates.
The study's findings encourage discussion on how we approach conservation and climate change. Carnivoran and ungulate communities are more influenced by past climates, whereas primate communities are more affected by modern climates. The image below (Figure 2 from Rowan J, Kamilar JM, Beaudrot L, Reed KE. 2016 "Strong influence of palaeoclimate on the structure of modern African mammal communities") shows how mammals overall are influenced by paleoclimate in comparison with carnivorans, primates, and ungulates specifically. Darker boxes indicate strong influence; as you can see, carnivorans and ungulates have mostly darker shades to the right, indicating influence during the mid-Holocene and Last Glacial Maximum.
This suggests two possible conclusions: one, that these species are more ecologically flexible than previously thought, or two, that they were prevented in following their preferred climate in the past several thousand years.
The overall temperature change from the last ice age to the new, warmer world was only 4 to 7 degrees Celsius, and this took place over 5,000 years. With human influence (read: carbon emissions) maintaining the status quo and refusing to use more sustainable fuel options, this temperature increase will happen much more quickly (we've already increased the global temperature nearly one degree Celsius since 1880; shoutout to the Industrial Revolution).
Primates are incredibly picky when it comes to environment and are typically biome-specific. Don't believe me? Think about all the "snowbirds" who leave New England for Florida in the winter.
Most primates live in forests; as a result, they are negatively affected by forest fragmentation. Declines in forest area and increases in forest fragmentation can be caused by climate change. It can also be due to human activity--such as logging, mining, and hunting for bushmeat--and, well... it's not good.
In Madagascar, food shortages have led to both deforestation (to make room for more farmland to try to circumvent the shortage), as well as active hunting of lemur populations by local people for food. Forest interiors have different microclimates than forest edges; among other things, this can alter the host-parasite dynamic, creating infections and increasing a group's vulnerability. In Asia, orangutans live semi-solitary lives (males often live alone) and are primarily arboreal (they almost exclusively move through the trees). Thanks to humans cutting down large swaths of forest or intentionally setting fires that not only destroy habitat but also burn slow-moving orangutans to death, survival and reproduction for these groups have become increasingly more difficult.
Human activity is literally killing other primates. If we destroy forests completely or create a patchwork forest or continue to engorge ourselves on fossil fuels, we aren't giving these mammals/primates/living beings a chance.
So, back to that study about paleoclimate and the two possible conclusions. Some mammals are more ecologically flexible than previously thought or they were prevented from tracking their preferred habitat during the past several thousand years.
Of the groups in the study, ungulates were the most influenced by paleoclimate. These mammals live in savanna habitats that have been pretty much the same for thousands of years. They eat leaves and grasses, which occur across a number of biomes, lending them great ecological flexibility. On the other hand, primates often eat fruits and, therefore, are more tied to forests. Primates are not as flexible, and seem to be adapted to modern climates more so than paleoclimate.
Overall, the study's results suggest that future changes in habitats as a result of human activity will affect mammals differently, depending on how sensitive they are to change.
What often gets shoved under the rug is the fact that processes of evolution and adapting take time. And I mean a lot of time. Normal climate change occurs gradually, slowly. Climate change today is not gradual or slow. Humans have greatly increased the rate--will life be able to keep up?
We, ourselves, are primates. What happens when we can no longer survive in our environment?