What are the causes of climate change?

CO2 is important to life on earth…

Carbon dioxide is a greenhouse gas that warms the lower atmosphere. Naturally produced CO2 is an important atmospheric gas that traps heat and without it Earth would be “frozen solid and lifeless at an average temperature of -18 Degrees centigrade”.Nasa

but human activity is increasing carbon emissions beyond what can be absorbed by the earth…

Human produced greenhouse gases are small compared to natural emissions: around 23 billion tonnes of CO2 compared to 776 billion tonnes of CO2, a point often made by climate change sceptics; however equally large amounts of CO2 are re-absorbed as part of the natural carbon cycle – around 788 billion tonnes a year. Natural absorptions roughly balance natural emissions. What human activity is doing is adding an extra layer of carbon emissions, only some of which are absorbed by the oceans and land plants but around half of which remains in the air, trapping heat and leading to global warming.

…or the oceans

Rate of ocean acidification are unprecedented. CO2 dissolves in water to form a weak acid, and the oceans have absorbed about a third of the CO2 resulting from human activities. Carbonic acid makes the ocean’s chemistry less hospitable for many forms of marine life. Ocean acidification is now happening at an unprecedented speed, one far greater than previous mass extinctions in Earth’s history as a result of ocean acidification.

Naturally occurring climate change leading to mass extinctions has happened before – but that leaves no room for complacency.

Detailed scientific evidence based on geological records shows that major climate change has occurred in the past leading to mass extinctions of species (for example in the miocene period 16-14 million years ago). The same evidence shows that this time round, it is human activity which is responsible for climate change – and it is happening at great speed. Moreover, references to past climate change and mass extinctions by sceptics is hardly re-assuring given that current climate change poses an existential threat to humanity and other forms of life on earth.

The Royal Society of Science sets out human produced greenhouse gases which include:

  • Carbon Dioxide (CO2) – the biggest contributor to global warming resulting from the burning of fossil fuels, cement production, and deforestation
  • Nitrous oxide from agricultural fertilisers: Nitrous oxide (N2O) concentrations have risen primarily because of agricultural activities such as the use of nitrogen-based fertilisers and land use changes.
  • Halocarbons, including chlorofluorocarbons (CFCs) While Chlorofluorocarbons (CFCs), were banned because of their impact on the Ozone layer, their replacements, along with other halocarbons are also potent green house gases
  • Methane (CH4) levels have risen significantly since pre-industrial times due to human activities such as raising livestock, growing paddy rice, filling landfills, and using natural gas

Economic growth and climate change

Any truthful discussion of the causes of climate change cannot be confined to a technical and scientific explanation of green house gases resulting from the burning of fossil fuels. It needs to examine the over-arching cultural, economic and political context in which runaway greenhouse gas emissions take place. While greenhouse emissions are the proximate cause of climate change, the ultimate drivers are market forces that persistently externalise environmental costs. In other words, market price for the products we buy and sell take no account of the real costs and damage we are doing to environment and the wider biosphere on which all life on earth depends.

The urgency with which this issue is rapidly coming to the fore is spelled out by Naomi Klein: we are all complicit in a highly exploitive form of capitalism; market fundamentalism is killing the planet and we need to come out of denial. Polite incremental change that attempts to bend the needs of the planet to an economic model of constant growth has failed and we need radical action.

Many will recoil at such blunt language and deem it ‘anti-capitalist’. But the stakes could not be higher. If, in the highly unlikely event climate change is later found to be far less of a challenge to life on earth and human civilisation in particular, many of our most reputable scientists will have eggs on their faces – a small consequence and minor inconvenience to those involved. If on the other hand they are right, then the consequences are unimaginable not just for human civilisation but for human and all life on earth. Prudence dictates taking immediate action and not waiting for every issue to be resolved – nor indulging in political polemics and point scoring debates that have more do do with narrow commercial interests and ideological belief than in any evidenced backed deliberation based on genuine concern for the wider good.

The biggest source of planetary-boundary stress today including climate change and threatened ecosystem collapse, is excessive resource consumption by roughly the wealthiest 10 per cent of the world’s population, and the production patterns of the companies producing the goods and services that they buy[xviii]. Around 50 per cent of global carbon emissions are generated by just 11 percent of people and around57 per cent of global income is in the hands of just 10 per cent of people. Adding to the pressure created by the world’s wealthiest consumers is a growing global ‘middle class’, aspiring to emulate today’s high-income lifestyles based on an inefficient and exploitive use of natural resources reliance on oil.

Why it’s time for doughnut economics

A devastating critique  and crash course in the predominant economics model is provided by the celebrated economist Kate Raworth in this dramatic TEDx presentation. More importantlsy she also outlines an alternative economic model to that based on narrow economic growth.  However, as she says herself, this presentation is “not for the faint hearted” because the measurements she presents using her model reveal the full scale of the challenges that humanity now faces. This is a brilliant presentation that sets out a new vision and way of understanding the economy along with ways of measuring what really matters.

Advertisements