A Brief Summary of Climate Science - The Problem and the Solution
Global warming, caused by an increase in greenhouse gases in the atmosphere since the Industrial Revolution, is causing the earth’s temperature to rise and the climate to change.
Greenhouse gases, like carbon dioxide and methane, form a layer in the atmosphere that acts like a blanket trapping heat from the sun inside our atmosphere.
This is causing the Earth to become hotter - we have already exceeded a 1C rise in the average global temperature.
Over 99% of the world’s climate scientists agree that the climate is warming and it is the result of human activities, which have accelerated since the Industrial Revolution.
Global warming is caused by human activities including:
- Mining and burning fossil fuels (coal, gas and oil) for electricity and transport;
- Land clearing which removes trees and vegetation available to take carbon dioxide out of the atmosphere, while the burning of this vegetation releases more carbon dioxide into the atmosphere;
- Agriculture, industrial processes and emissions from waste.
In Australia most of our emissions come from burning fossil fuels for energy.
Australia’s greenhouse gas emissions by sector:
The Impacts of Global Warming
The last five years were the hottest five years since the National Oceanic and Atmospheric Administration (NOAA) began keeping records 139 years ago.
These hotter temperatures are causing more frequent and more extreme weather events including bushfires, storms, droughts, floods and cyclones.
Heat waves are becoming more frequent and more deadly.
The increased temperature is causing glaciers and ice caps to melt. This melted water is running into the oceans causing sea levels to rise. Sea levels have already risen 230mm since 1880 (the time of the Industrial Revolution) and this has accelerated in the last decade to a current annual rise of 3.3mm (ref: NASA).
In Australia some of the worst impacts in recent decades have included:
- The current drought in NSW and southern QLD is the worst on record.
- Declining rainfall and looming water shortages in many parts of NSW, southern QLD, Victoria, South Australia and Western Australia.
- Increasing numbers of bushfires such as the Black Saturday bushfires in Victoria (2009), fires in Tasmania in 2018 burning millions of hectares of World Heritage forest, and 200 fires in southern Queensland in November 2018, some in areas that have never before seen fire.
- Hotter and longer heatwaves, which have resulted in the deaths of many people, animals and plants, for example 23,000 spectacled fruit bats died in the Cairns area in November 2018 which was one third of the entire species population. (ref: BBC)
- About 50 per cent of the coral on the Great Barrier Reef have died since mass bleaching events in 2016 and 2017 caused by the increased sea temperatures and ocean acidification. (ref: National Geographic)
The US Department of Defence has long warned that climate change is a national security issue with potentially millions of people becoming climate refugees worldwide as their homelands become uninhabitable due to flooding, fire or drought.
The World Economic Forum describes climate change as the number one threat to the world economy and the World Health Organisation warns of the many health threats that climate change poses to humans.
And perhaps the greatest threat of all is the risk to the world’s food supply. The IPCC released a report in August 2019 stating that climate change and the over-exploitation of land and water resources poses a massive threat to world food supplies.
What is being done about the climate crisis?
While climate scientists have been warning world leaders about global warming since the 1970s, with a consensus emerging in the 1990s, the world was slow to react.
After numerous gatherings of world leaders, the most significant step forward came in 2015 when a global agreement was reached in Paris at the United Nations COP 21 meeting. For the first time in history all nations agreed to reduce greenhouse gas emissions in order to restrict global temperature rise to below 2 degrees Celsius above pre-industrial levels, with efforts to stay below 1.5 degrees temperature rise.
However even with the commitments made in Paris, the world is still on track for at least 3 degrees Celsius of warming. The commitments were not sufficient, even if all countries were to meet their agreed targets.
In October 2018 the Intergovernmental Panel on Climate Change (IPCC) released a special report on 1.5 degrees of warming. It documented the necessity to stay below 1.5 degrees of warming in order to have a 50% chance of avoiding the most catastrophic impacts of climate change, and that to achieve that required a 45% reduction (from 2010 levels) in greenhouse gas emissions by 2030 and net zero carbon emissions by 2050.
All countries need to increase their targets and take emergency-scale actions to reach these goals if we are to avert catastrophe.
Australia is one of the laggards in climate action. We have one of the highest per capita emissions in the world - a with just 0.3% of the population we emit 1.3% of global emissions. But we are actually the fifth largest carbon polluter globally when our exports are included - up to 5% of global emissions.
And, if we continue our current rate of fossil fuel mining, burning and exporting, it is projected that we will be responsible for 13% of global emissions by 2030.
The solutions are already coming - despite government inaction
A vast array of solutions to rapidly reduce our greenhouse gas emissions are already available and are economically feasible. These include replacing 100% of fossil fuel energy with renewable energy sources such as wind, solar, hydro, geothermal, biomass and green hydrogen power.
Storage of renewable energy has also developed at a rapid pace. Large battery banks, as well as technologies such as solar thermal with molten salt storage or pumped hydro power, are able to store energy to send into the grid when the sun isn’t shining and wind isn’t blowing!
In Australia for several years already it has been “cheaper to build a wind or solar farm than to build a coal or gas power station.” And “it is now the same cost or cheaper to build a new wind or solar plant in Australia than to continue operating old coal power stations in New South Wales and Queensland.” (Ref: The Climate Council)
Wind and solar power are being installed in Australia at an encouragingly fast rate.
South Australia has already installed a combination of solar, wind and battery storage and is set to reach 100% renewable energy by 2030, even exporting green energy into the national grid and overseas. It currently gets at least 50% of its energy from renewables in 2019, reaching 100% on very windy and sunny days.
Electric vehicles are also starting to replace internal combustion engines, and advances are being made in more difficult sectors such as aviation, shipping and cement.
The developing world is embracing renewable energy technologies. What we need is the political and corporate will to urgently implement these solutions, whilst ensuring a fair transition away from the old, greenhouse gas-emitting technologies.
Fossil fuels such as coal, oil and gas helped our country prosper; we need to recognise the role these industries and their workers have played in our country’s history, and help them develop alternative industries with decent wages in their communities.
Are we doomed? Can humankind really solve this and avoid extinction?
There are many writers and researchers who have written articles and reports asserting that it is too late to save ourselves from climate catastrophe and probable extinction.
This is not the view of most climate scientists, who state that we still have a narrow window of time to save ourselves and the planet.
Action to avert climate damage needs to be taken swiftly and boldly, mobilising all sectors of society as has been done in world war mobilisations, to protect our planet and our children’s futures.
It is true that predicted impacts of global warming vary between models, and we heed advice that many predictions of the Intergovernmental Panel on Climate Change (IPCC) are on the conservative side. Thus, we treat the IPCC recommendations as the minimum required.
The recent report from the IPCC, “Global Warming of 1.5 ºC”, explains that collectively we need to reduce greenhouse gas emissions by 45% by 2030 (on 2010 levels) and to net zero by 2050 to have a 50-66% chance of limiting global warming to 1.5 ºC. These climate experts argue that 1.5ºC is a necessary goal to aim for to give the world the best chance to avoid the worst effects of catastrophic climate change, to give our children a liveable, healthy, thriving planet on which to grow old.
The targets set by scientists and legislators depend on differing interpretations of mitigation and adaptation options, as shared by famous climate scientist Katharine Hayhoe.
We are already at risk of global food shortages, fires and coral die off as early as 2040 if we reach 1.5°C warming
At a 2°C rise these problems would be even greater. But a bigger issue with 2°C is how we could then stop the world continuing to warm even more over coming centuries.
But a 50% chance of staying under 1.5°C hardly seems good enough. You wouldn’t get on a plane with only 50% chance of landing safely, would you? So the climate emergency goals make sense. We must do all we can to reduce emissions ASAP.
In response to the predictions made by the IPCC and other climate scientists, climate activist groups have developed their own demands, such as transitioning to 100% renewables and zero emissions by 2025 (eg. Extinction Rebellion), or by 2030 (eg Australia’s School Strike For Climate, The Sunrise Movement and the Green New Deal in the USA).
We endorse these goals and highlight that this is still in the bounds of what the IPCC 1.5C special report is asking for. So we can go into emergency mode, and support the climate emergency mobilisation movement to protect our kids’ liveable world, but at the same time we can trust the scientists who wrote the IPCC 1.5C report.
It is easy to get terrified by some of the worst-case scenarios presented in the climate emergency movement. We can acknowledge these worst-case scenarios, and focus our energies on working to avoid them.
While recognising that the IPCC 1.5 C is scary enough and remains our guide for taking action, some scenarios are more likely than others. This resource here explains tipping points and future projections in a relatively easy to understand way.
Long term, carbon capture technology and geo-engineering like solar radiation management may be needed but the best actions we can call on government and industry to take now are to reduce emissions, invest in renewables, protect forests, and transition to a more sharing economy.
The IPCC puts it simply:
“Every action matters
Every bit of warming matters
Every year matters
Every choice matters”
Climate scientist, Katharine Hayhoe, says “But the bottom line is this: it's true some impacts are already here. Others are unavoidable. But my research, and that of hundreds of other scientists, clearly shows that our choices matter. It is not too late to avoid the worst impacts. And that's why... the best thing you can do about climate change is talk about it."