Climate change: causes and remedies

Causes

Climate change is caused by an increase in the earth’s temperature, brought about by natural and human causes.

Natural causes?

Natural causes of global temperature rise can include volcanic activity, a change in the energy from the sun and variations in the earth’s orbit around the sun. However this is little evidence of dramatic changes in any of these factors sufficient to account for the dramatic temperature increases of the past few decades. So scientists are now 90% sure that the major source of the increased gases is human activity.

Human causes?

The so-called Greenhouse gases in the atmosphere (water vapour, carbon dioxide, methane, nitrous oxide and chlorofluorocarbons) trap the sun’s energy which reaches the earth, reducing the amount reflecting back into space, thus warming the earth’s surface. The burning of fossil fuels for energy generation, in industry and for transport, plus agricultural activities (land clearing, fertiliser use, flood irrigation and stock) have significantly increased these gases since the industrial revolution.

Sceptics vs science

Sceptics are still arguing this point, but the consensus of scientists and scientific organisations around the world now supports the conclusion that the major causes are human, not natural. This includes reputable organisations such as the US national Aeronautics and Space Administration (NASA), the Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the European Academy of Sciences and Arts.

There are a few reputable climate scientists among the sceptics, but most of the sceptical comments I have seen have been based on obvious mistruths – see A climate change conspiracy?.

Remedies

To reduce the future impacts of climate change, we obviously need to reduce the amount of greenhouse gases we put into the atmosphere and to stabilise them at safe levels. In particular, we need to reduce the amount of carbon going into the atmosphere, by:

• moving to less polluting energy generation, transport and other industry
• developing new agriculture methods
• re-forestation
• using less animal products, especially in food
• carbon sequestration (storage of carbon rather than allow it to enter the atmosphere)

Studies show that, in Australia and globally, the three largest sources of greenhouse gases are:

1. “stationary energy” – fossil fuels consumed in power generation, domestic and commercial heating and in industry;
2. transport; and
3. agriculture and deforestation.

It is becoming economically feasible to move most of these uses away from fossil fuels.

Stationary energy

Reduction of greenhouse gases from stationary energy usage will involve:

• electricity generation by solar, wind, tidal, geothermal, hydro or other renewable technologies that produce minimal greenhouse gases – we must leave most of the remaining coal in the ground;
• heating of buildings by electricity rather than gas, oil or other fossil fuels;
• greater insulation of buildings to reduce energy usage; and
• more efficient heating, lighting, appliances, etc.

Beyond Zero Emissions, an Australian Think Tank, has prepared a plan that would move Australia’s stationary energy production almost totally to renewable energy (mostly solar and wind) within ten years, at a modest annual cost per household of $400, which is less than 1% of average household income, and the estimated cost of providing conventional coal-generated electricity.

In other words, the additional cost of renewable energy for this usage is zero!

This plan is not government policy, unfortunately. But elsewhere in the world, plans to substantially increase the use of renewable sources of energy are well underway, with Denmark, Germany and the UK among the leaders.

Besides reducing greenhouse gases. Renewable energy has the advantage of generating more jobs than fossil fuel production.And as usage increases, costs are coming down, and will soon be competitive with fossil fuel.

Transport

Reducing the generation of greenhouse gases for transportation involves greater use of electric cars and development of improved electric-powered public transport (e.g. high speed inter-urban rail, and urban light rail). The technologies are available now, and will only get better and cheaper.

Agriculture and deforestation

Land clearing and animal wastes are the two main causes of agricultural greenhouse gases. On the other hand, agriculture and forestry can draw carbon dioxide out of the atmosphere by sequestering it in growing plants and in the soil.

Thus modest but important changes in land use practices can yield benefits.

The problem

The technologies are either available or within sight. The costs are coming down all the time. We can reasonably hope that reducing greenhouse gases to the level required to prevent most of the worst effects of climate change is practically possible.

The real problem isn’t technology, or economics.

The experts say that the real problem is political will. Some of the world’s richest companies are fossil fuel companies (according to the Fortune 500 list for 2015, petroleum companies rank 2nd, 3rd, 4th, 5th and 6th globally by income) and they stand to lose if the world switches to renewable non-fossil energy.

These companies have enormous political clout, and use it to influence politicians. Some say this is done in clandestine and underhand ways. In some cases (e.g. the Murdoch press), the media support them.

If the world is going to make the necessary changes in time, we will have to press the politicians to refuse to be influenced and intimidated by the wealthy fossil fuel industry.

You and I can …

There are some actions we can all take – eat less meat, pay carbon offsets when we travel by plane, use more energy efficient transport and use less energy at home (avoid air conditioners!). But the most important response we can make is to support political action to provide incentives for more efficient energy generation, transport, industry, mining and agriculture by being willing to pay more for goods and services.

The bottom line

Whatever happens, our cost of living will likely increase – either by taking remedial action now, protecting our planet and the lives of millions of people, or by continuing to vacillate, condemning millions of people to disaster and paying the inevitable cost of the problems which climate change will bring.

There’s no real choice, is there?