Author: Dr. Ken Elliott
This winter McGill University hosted their annual public lecture series called "MiniScience" in which faculty members with extensive experience deliver fascinating in depth presentations - this year on issues of sustainability. Topics included:
Slash and Burn agriculture in Amazonia,
Water in the Andes
Doing chemistry with less
Development in China
Global food security
Here are some of my reflections after listening to a lecture presented by Prof. Andy Gonzalez, titled “Biodiversity Change and Sustainability in the Anthropocene" - a look at the state of the planet in terms of the impact of humans on it. Prof. Gonzalez highlighted the interconnectedness of the many different types of actions by humans on many different aspects of nature: The deforestation of so many regions of the world, the elimination of habitats of so many species of plants and animals, the pollution of air and water on such a vast scale, and the build-up of carbon dioxide and other greenhouse gasses. He pointed out that, up to the industrialization of the world, it has been natural factors that have caused the many changes on the planet over the past millions (billions) of years. These changes include: climate warming and cooling, mass extinctions of animal and plant species, ice ages, changes in geological structures - mountains, rivers, coastal areas- and changes in habitats for flora and fauna to name but a few. They used to be the result of natural phenomena like volcanoes, catastrophes like meteor collisions, and other naturally occurring variations.
Over the past few hundred years, however, there has been an accelerating effect of the Anthropocene on our natural world. In other words, more and more, it is humans that are causing these changes. Most climate scientists agree now that the climate is warming at an alarming rate (although there is not universal agreement about the rate of change) and that this is a direct result of the rapid increase of the amount of greenhouse gases (especially CO2) from industrial processes and combustion from different forms of transportation. With the exponential growth in the human population, land use has been taken from its natural purpose and been turned over to human uses like housing, roads, farming, urbanization. The habitats of many species of animals and plants have been destroyed by human activity, driving the natural inhabitants out or, worse still, causing their extinction. There have been 5 naturally-caused mass extinctions documented by scientists over the geological history of the earth. A mass extinction is defined as the loss of 70% of all species. Dr. Gonzalez postulates that we are at the beginning of a 6th - and this time it is being caused by human activity.
In an article, cited by Dr. Gonzalez, which cites hundreds of research articles on the Anthropocene in the Journal Nature, Cardinale et al (2012) emphasize the ecological damage that humans are now inflicting on the fragile earth's ecosystems. "The most unique feature of Earth is the existence of life, and the most extraordinary feature of life is its diversity. Approximately 9 million types of plants, animals, protists and fungi inhabit the Earth. So, too, do 7 billion people. Two decades ago, at the first Earth Summit, the vast majority of the world’s nations declared that human actions were dismantling the Earth’s ecosystems, eliminating genes, species and biological traits at an alarming rate. This observation led to the question of how such loss of biological diversity will alter the functioning of ecosystems and their ability to provide society with the goods and services needed to prosper."
It remains to researchers to continue to study this situation and look for solutions and to school teachers to make this topic an important part of school curricula so that we can all become part of the search for solutions.
Bradley J. Cardinale, et al., 2012, Biodiversity loss and its impact on humanity. Nature 486, p 59-67.