Climate and biodiversity – Part II

The pressures exerted by climate change on ecosystems are comprehensive::

  • extreme weather events (such as droughts, heat waves, storms or very strong winds);
  • the unsynchronisation of key events in the life cycle of animals and plants that are evolutionarily linked in different ways (e.g. providing food for each other or helping each other to reproduce – through pollination or seed transfer), which can result, for example, in a lack of food for chicks during the breeding season;
  • the need to leave their current habitats due to an inability to find new, suitable habitats
  • and many others (source)

As a result, according to estimates from the IPCC’s 4th Report, 20-50% of species face extinction with a 2.9°C temperature rise, and as many as 40-70% of species with a 3.5°C warming (link). There are sources that suggest the figure will be reduced by up to half (link), others forecast that it could be even worse( link i link). It is not just a question of climate change itself, but above all the rapid rate at which it is occurring, and other factors such as our infrastructure preventing species migration (fragmentation of ecosystems by roads and built-up areas), the takeover of natural ecosystems for agricultural monocultures, the use of pesticides and herbicides, water, soil and air pollution, saturation of the environment with harmful chemicals, deforestation, hunting, etc.

Taking species extinction conservatively below the lower end of the IPCC’s projection of climate-induced species extinction in a business-as-usual scenario, we can expect 30% of species to become extinct by the end of the century. With the number of species estimated at 10 million, this will mean the death of 3 million species. The average 1 GW coal-fired power plant will contribute 1.3 per mille to the world’s total emissions (annually 7 million tonnes of CO2 out of 55 GtCO2e of total anthropogenic emissions), so statistically speaking, emissions from this one power plant will cause the extinction of 400 species – with, of course, no specific species attribution possible (source).

Much will depend on the extent to which our adaptation measures take into account the needs of the ecosystems. If, for example, we decide to maintain the course of the coastline by building high embankments, this will mean that a concrete wall will stretch for miles in place of the current rich coastal ecosystem – from small invertebrates to birds and seals. Protected areas will also require a change in approach. In a world where individual national parks and reserves are separated from each other by our fields, roads and cities, species migrations will be extremely difficult. Controversial ‘active conservation’, involving the active introduction of thermophilous species to replace those previously found in a particular place, may have to be considered.

This article was written with the consultation of Nauka o Klimacie