How Climate Change affects Biodiversity.

More often than not, in fact 90% of the time, the reason why we are concerned about climate change is selfish and self-serving.

We as human beings are concerned about us. How will climate change affect our lives, our livelihoods, our economies, our development, our security, food and otherwise. It’s all about us. Even in adaptation, we focus on, how we can save ourselves and the planet for our own benefit?

The Congo rain forest - thousands of species call this place home

Yet human beings are just one among the millions of species that call this planet home. These plants, animals, microbes do not have a voice and cannot participate in global debates that determine their welfare and survival.

In burning fossil fuels, we are just thinking of ourselves, of how we can develop our lot and move forward as a species. We caused the current global warming without thinking about the rest of the planet’s inhabitants who incidentally form the majority.

Now, how and what will climate change mean for biodiversity?

Biodiversity simply means the multiplicity of living things.

The impacts are direct and some are indirect. But a good majority is negative.

One of the most direct consequences of climate change on diversity is that rivers and lakes dry up. 
And that leads to the death of all species that depend on water during part or all of their lifecycle. For example, some types of snails move to water to hatch, while others just live in the water. All these, together with the species that feed on them will be gravely reduced in number as a result of climate change.

Human – wildlife conflict. As climate change becomes a reality, erratic weather patterns such as lack of enough rainfall will cause shortages of water as rivers dry up or groundwater level recedes. This in turn will lead to lack of food (due to crop failure) and drinking water for wildlife and human beings. 

People are most likely then to invade protected wildlife areas looking for food and water for their animals or themselves. Animals will invade farms and homes looking for food and water. In both these scenarios, there’ll be casualties as the two clash in the fight for the increasingly scarce resources.

There is also another dimension in the destruction of wildlife habitat by people seeking arable land or land for pastoralism. As more animals are concentrated in a smaller area, competition will increase for say, grass among herbivores. The weaker animal species will lose out and biodiversity is affected.

Also, chances are that land taken from wild flora and fauna will most likely never again be vacated by people in favor of the original wildlife inhabitants. The land taken over by people will be developed for human use that is, it is less likely to ever again regain the original mix of plants and animals that it originally had. For example, a farm that was hived off a game reserve is likely to promote growth of one or a few species of plants which are beneficial to man. The original plant species would be deemed as weeds and removed completely.

Poaching – As climate change intensifies and conventional and lawful ways of eking out a living are made harder by climate change, there is every likelihood that wildlife will be seen as a source of income in more ways than one. If an area occupied by both wild animals and people dries out and farming/pastoralism becomes a less sure source of income, then people are wont to look for other ways to get a livelihood. This is a classic case of the vicious circle whereby poverty and environmental degradation feed on each other. In this case, in desperation, more people will start selling wildlife trophies as a way of making money for sustenance.

With climate change, heat radiated by the earth is trapped by the atmosphere. This causes a rise in atmospheric and surface ocean temperature. This heat then causes mountain glaciers in equatorial peaks to melt. This has been documented in the Ruwenzori Mountains in Uganda, Mt Kenya and also the Kilimanjaro. The 0* degree line, the temperature at which water melts/freezes, keeps moving upwards. This could mean many things. Such glacier melt provides water for rivers if it is seasonal. But if the glaciers melt once and for all then there’ll be various consequences on dependent animal and plant life. If the glaciers melt once and for all, then river volume during the warmer seasons would be permanently low.

As the temperature goes up, then vegetation belts will also migrate upwards, each searching for its optimal clime. Glacial areas will turn to alpine areas which will turn to montane forests. The areas formerly occupied by montane forests will be occupied by lowland forests and progressively by grassland savannah which will then become arid and semi-arid areas. ASAL areas will turn to total deserts. The topmost levels like where giant lobelias grow will disappear and the plants will become extinct. Xerophytes which are desert plants like cacti will be the ones which will benefit the most.

Plant species will be affected more than animal species. This is because animals can move much faster than plants can. Seed dispersion methods are likely to play a huge role. For example, seeds dispersed by wind or by animals are wont to establish themselves in new lands upwards faster than those plants whose seeds are dispersed by natural force (like when the sun dries a seed pod and it bursts open with force which propels the seed further away from the parent plant).

Those plants species that can’t migrate fast enough will either have to adapt or die out. As the hot conditions continue, and the ocean invades land, it will bring with it new species. Vegetation alongside animals found next to oceans will start moving inwards.

Also, the changed climatic conditions will become conducive for invasive species. Invasive species are ‘visitor’ species. They are not ‘local’ or indigenous species. They are foreign to a given ecosystem and more often than not wreak havoc in the structures and functionality of that ecosystem. They increase competition for resources and having no natural predators generally thrive with flourish. So what will happen when say plant species A is practically wiped out by an invasive species? What about the role it plays? What if in human terms, it was a food crop or of economic importance?

Animal species will also be affected. In fact the entire food chain will be affected. If grass species die out or the acreage diminishes, then herbivores population and diversity will be affected too. This means that there’ll be fewer numbers of say gazelles within each sub species. What does this mean for carnivores? They lose variety in their diet which will affect nutrition. This will have a ripple effect, with nutrition affecting fertility and physical attributes such as skill and speed which in turn will affect survival of the species. Food scarcity implies that weaker members of a species also die because of their inability to compete effectively.

But the major thing affecting animals when it comes to climate change is direct loss of habitat due to climatic conditions. Habitat means the physical conditions that usually make up the environment of a particular species. When vegetation belts start moving upwards, narrowing or even disappearing altogether, the animals that are found in that habitat will also most likely reduce in number. For example, lions prefer savannah grassland to forests. If the grasslands belt moves upwards, then so will the lions which will be following food (herbivores) and optimal living conditions. If the savannah is reducing in size, then the lions will suffer.

The rate at which climate change affects biodiversity will depend on species (ecological) resilience. 

How fast can species adapt to changing conditions and come back to normal. How fast can they absorb shocks and rebound? Unlike human beings, animals can only adapt naturally. They do not have the resources at our disposal. They don’t have our level of intelligence or any type of technology. That means that they will have to evolve naturally. This can take from a few hours (microbes) to hundreds or thousands of years.

Some species are naturally resilient. This includes tree species which can live for hundreds of years like giant oaks, ebony dark wood and others.

Forests and forest species will also be affected. How? We’ve already covered invasive species but there’s also frequency in occurrence of ‘natural phenomena’ like wildfires like those witnessed in America and Canada this year and last year. Hurricanes and long extended droughts will directly destroy forests and the thousands of resident species.

Climate change will also affect temperature, and availability of water, important factors in plant growth. This will in turn affect lifecycles and growth patterns. How will this affect animals in the forests? Well, an example. A certain butterfly species depend on the flowering of a certain tree, maybe to lay eggs or find nutrition for the larva. This tree, lacking enough water or it being too cold or too hot flowers much later. The butterfly larvae die of starvation. Butterfly numbers are reduced. Say a type of monkey depends on fruits that are produced by a particular type of tree at a given time of the year. The tree affected by climate change, ‘fruits’ much later or in a lesser quantity. What happens? There’s food scarcity in the forest.

How else will climate change affect forests? Changes in weather conditions will affect numbers of pathogens and predators. Pathogens are harmful disease causing bacteria, protozoa or viruses. Predators are those that prey on (eat) others. These species are important in nature and helps keep populations in check. That is, the number of one type of animals doesn’t get too big and thus hugely inconvenience others. It’s a system of balance and checks in the ecosystem. But if these pathogens and predators spurred on by favorable changes in climate, get out of control, then some types of prey forest plants or animals will become extinct or be gravely reduced in number.

Now if we could go back to high school geography, the physical earth is made up of several layers, the crust, mantle and the core. The crust is made of sial (main minerals: silicon and aluminium) which is on top of the sima (main minerals: silicon and magnesium). The continents are part of sial while the oceans lie on top of the sima. That means that oceans are very deep and are stratified in layers determined by temperature and density. They experience a phenomenon known as thermal inertia which basically means that it takes a very long time for ocean temperatures to change. But when they start changing it will also continue slowly until long after surface temperatures have stabilized. In other words, the current global warming will continue to affect the inhabitants of the deep for centuries to come. The surface layer is the layer which is most affected by natural phenomena such as atmospheric temperatures, waves produced by wind (they mix up the water). It also allows sunrays to pass through. The rays warm up the water and allow for photosynthesis which allows a diverse plant and animal biome.

Part two will be uploaded soon.