As featured in Waterline Spring 2021
Global Warming and Climate Change
Sources of Greenhouse Gases
The most concerning greenhouse gases are water vapour, carbon dioxide and methane. Other greenhouse gases which have a smaller effect on global warming are ozone, nitrous oxide and chlorofluorocarbons.
Water vapour has always existed in the atmosphere, but with warming oceans and planet an extra 7% of evaporation is adding to the previous levels.
There are both natural and human sources of carbon dioxide emissions. Natural sources include decomposition, ocean release and respiration. Human sources come from activities like cement production, deforestation as well as the burning of fossil fuels like coal, oil and natural gas.
Methane is emitted during the production and transport of coal, natural gas, and oil. Emissions also result from livestock and other agricultural practices such as anaerobic digestion in natural wetlands and in paddy fields, and by the decay of organic waste in municipal solid waste landfills. A newer source is from melting permafrost. Interestingly there is 8-10% more methane in the Arctic atmosphere than in the Antarctic atmosphere. Methane is a stronger greenhouse gas than carbon dioxide because it has much higher heat trapping ability. Methane on a weight basis has 21 times the global warming potential of carbon dioxide. Thankfully there is a lot less methane than CO2 in the atmosphere.
In the UK, transport is the largest emitter of carbon, through road, rail, sea and air, accounting for some 28% of emissions. Industry is second with 23% of all emissions, with 4% of that total coming from upstream oil and gas extraction. This is not a competition, but in third place are buildings with emissions at 19% of the UK total, of which residential buildings account for 14.8% with public and commercial buildings accounting for the other 4.2%. Animal farming and other natural resources such as forestry add 15% as does power generation and distribution.
Globally, the primary sources of greenhouse gas emissions are electricity and heat (31%), agriculture (11%), transportation (15%), forestry (6%) and manufacturing (12%). Energy production of all types accounts for 72 percent of all emissions.
A little bit of Earth’s History
In Earth’s long history it has been through at least 5 mass extinction events. Most were caused by cataclysmic volcanic eruptions. It wasn’t the lava or ash that wiped out life, but a gas released by the volcanoes, carbon dioxide.
Almost every part of modern life depends on energy generated by burning fossil fuels which produce CO2 in huge amounts. Globally we now release 100 times more into the atmosphere than all Earth’s volcanoes combined. If we do not confront this life threatening issue we are likely to lose over half the species of life on earth.
The last mass extinction event, 65 million years ago, which ended the reign of the dinosaurs was caused by massive and rapid climate change* resulting in the destruction of 75% of plant and animal life on earth. Scientists say humans have negatively impacted the planet to such an extent that we are moving into a new geological era in history, The Anthropocene Epoch.
*There is debate among scientists as to whether the primary cause was from a massive asteroid or comet impact, subsequently blocking out the sun and cooling the planet, equivalent to a ‘nuclear winter’.
Our Warming Planet
Governments have committed to keeping warming to no more than 1.5 degrees Celsius in order to limit catastrophic impacts. Currently we are on track for at least a 4 degrees Celsius increase.
Data from the EU’s Copernicus Climate Change Service has shown that 2020 was jointly the hottest year on record, tied with 2016. Since October 2020 through to March 2021 the world has been under a global cooling effect known as La Niña, so 2021 is likely to be slightly less hot, but this is only a blip in the records.
The warming of the Earth is primarily due to the accumulation of heat-trapping greenhouse gases, and more than 90 percent of this trapped heat is absorbed by the oceans. As this heat is absorbed, ocean temperatures rise, oxygen levels fall and water expands. Recent studies estimate that warming of the upper levels of the oceans accounts for about 63 percent of the total increase in the amount of stored heat in the climate system from 1971 to 2010, and warming from 700 meters down to the ocean floor adds about another 30 percent.
On land we have seen huge, dramatic bush and forest fires, most recently in California, Russia, and across much of Australia, with an intensity not seen before. These fires have released enormous amounts of CO2, and have destroyed wildlife habitats, peoples’ homes, and life. At least 30,000 Koalas died in the Australian bush fires, let alone the numbers of other species. California called its wildfires ‘gigafires’, after a one million acre fire in northern California.
Summer sea-ice in the Arctic has shrunk by 40 per cent in the past 40 years and could be gone entirely within the next few decades, removing a necessary habitat which enables polar bears to hunt and feed.
Land and ocean ice and snow deposits reflect the sun’s energy back out to space. Oceans are much darker than land, such that ocean snow and ice loss causes a significant increase in absorbed heat. Touch the metal surface of a black painted car on a sunny day to see for yourself how much heat is absorbed by dark surfaces.
Perversely our good intentions of improving global air quality has resulted in less of the sun’s energy being reflected back into space by airborne particles, increasing the energy we receive.
Sir David Attenborough has stated that our planet has been in one of its most stable periods for the past 10,000 years, with the average temperature varying by less than one degree Celsius in that period. He then added that the Earth’s temperature has risen by a whole degree in his lifetime, (95 years and counting) mainly as a result of burning fossil fuels. To slow global warming, let alone reverse it, we have to stop emitting CO2 into the atmosphere.
Air pollution from vehicle exhaust
As the planet warms it creates more extreme droughts, fires, floods and coastal erosion, making an environment which is increasingly difficult for many life forms to survive. Climate change is real. We can see it in the change of global weather patterns. As pole ice melts we introduce more fresh water into the oceans. Unlike melted salty sea ice (which sinks and drives global currents) the fresh water doesn’t sink and slows down current flow and distribution of nutrients.
Oceans evaporate 13m tonnes of water per second. The spin of the earth and winds determine distribution of the forming clouds and the subsequent, more concentrated precipitation. With a more energy rich atmosphere wind patterns are changing. Plants and animals depend on reliable, regular annual rains or drought periods in order to know when food will be in abundance and when is the best time to mate or lay eggs.
In 2020 African rains came early whilst the South Asia monsoons were late, the latter event causing a period of water scarcity for both animals and humans.
The change in the distribution of rains, and their intensity, is leading to major floods in some areas and increasingly dry lands elsewhere. The numbers of hurricanes and cyclones are increasing in size and power as they draw heat energy from the oceans. The hurricanes that hit the Americas travel on the gulf-stream and reach Ireland and Great Britain where storm winds and tropical style rains hit the two islands. Raging seas do much damage to coastlines, causing costal erosion such as washing away of sand beaches, cliff face collapses and salt water ingress onto the land. Most of the coast of England, the east coast of the US and the south coast of Australia have been identified as at the highest risk globally.
We are witnessing more extreme weather events: Siberia experienced a temperature record high of +38oC in 2020, Texas this year set a winter storm record low temperature of -10.5oC plus wind-chill, and in February, Germany saw the temperature change in 24 hours from -24oC to +18oC.
State of our Oceans
Oceans create 70% of the oxygen we breathe, (with around 20% coming from the Amazon rain forest). The oceans phytoplankton traps carbon and releases oxygen.
Life in the oceans provides food for an estimated 3 billion people. Ocean plants and animals absorb carbon throughout their life and when they die they take the carbon to the bottom of the sea. It has been calculated that since the start of the industrial revolution the oceans have absorbed up to a half of our CO2 emissions but that has come at a cost. When water absorbs CO2 it becomes more acidic and with warmer waters makes survival increasingly difficult for shell making creatures, coral reefs, and some phytoplankton, the amount of which has fallen 40% in recent years.
Overfishing is now a major issue with a decline of 90% in predatory fish and fewer fish overall, which means the marine system now stores less carbon.
Warming is reducing oxygen levels and many fish species are migrating to cooler waters.
5% of the oceans are marine protected zones with United Nation plans to raise that to 30%.
Global Mass Migration
Australian based Institute for Economics and Peace has warned that more than a billion people could be pushed into unliveable extremes by 2050, leading to one of the greatest human migrations in history. Rising sea levels, water scarcity, and land degradation are all expected to contribute to people having to move.
At the UN Security Council, in February 2021, it was estimated that 9.8 million people were displaced in the first half of 2020 due to natural and environmentalist said that the current global human population of seven billion is already using the resources of one and a half planet Earths. With the population likely to reach nine billion within thirty years the lifeboats that migrants seek are likely to be overwhelmed. disasters. Jeremy Rifkin, economist
Where did we go wrong?
According to Rifkin the problem is that over the past 2 centuries we dug up the burial ground of a previous geological era in history, the carboniferous era, and we took those dead remains in the form of oil, gas and coal and we made an entire industrial civilisation based on these fossil fuels.
As wealth and population grew we demanded more from the land and the seas. Humans cut down forested areas to create farm land to grow crops to feed themselves. They hunted and fished to great excess leading to the extinction of thousands of species, and of those that survive to this day many are classed as critically endangered. Humans are still cutting down over 15 billion trees each year. There are just over three trillion trees in the world, a 200 years supply at current rates.
Half of all fertile land on Earth is now used for farming, which is what separates us from other animals and what allowed us to form large population centres. David Attenborough believes that we’ve gone too far now though, destroying whole habitats just to feed humans.
Humans make up 1/3 of the mass of animals on Earth. This must be the clearest evidence of how humans have made the Earth theirs at the expense of anything else. 60 per cent of the mass of animals on Earth is taken up by animals we raise to eat. Attenborough says that the planet can’t sustain seven billion humans all eating meat, and that going vegetarian really will save the planet. 70 per cent of the mass of birds on the planet are domestic. The vast majority of these are chickens kept for meat and eggs – one species out of 10,000 species of bird on Earth.
What have the countries of the world achieved to date?
There have been annual global conferences since countries signed up to the United Nations Framework Convention on Climate Change (UNFCCC) – a treaty that came into force in 1994. Conference of the Parties (COP) summits are held annually, hosted by different countries around the world. The 21st summit was held in Paris in 2015, and was known as COP21. During this conference the Paris Agreement, the first-ever universal, legally binding, global climate change agreement, was adopted. The Paris Agreement set out to improve upon and replace the Kyoto Protocol, an earlier international treaty designed to curb the release of greenhouse gases. Countries committed to targets to reduce their emissions to net-zero by 2050.
Some countries moved from coal to gas, and increased the importation of carbon intensive industry products (exporting emissions) rather than expanding home production, and used their own starting point to base their emissions reductions on. The UK is guilty as charged on all counts. It announced a new plan on the 4th December 2020 to aim for at least a 68% reduction in greenhouse gas emissions by 2030, compared to 1990 levels. Much of that reduction has already been achieved during the past 30 years.
A French court has found the state guilty of failing to cut emissions in line with its own target, in the country’s first major climate lawsuit. The court ruled the state had displayed culpable failure by not meeting its goals. The court will return in the spring to decide whether to order the French government to take more stringent carbon-cutting measures, giving ministers another two months to demonstrate what they are doing to address climate change.
Most countries, including France and the UK, are engaged but as the young Swedish environmentalist, Greta Thunberg, said “you say you understand the urgency but you expect my generation to suck hundreds of billions of tons of your carbon dioxide out of the air with technologies that barely exist.”
I think the message is that we have started late and have an enormous challenge ahead, with a rapidly shrinking timescale in which to meet the target.
COP26 is the next annual UN climate change conference, which will be held in Glasgow, from the 1st to 12th November this year.
Coastal erosion of the cliffs at Skipsea, Yorkshire on the Holderness coast
Global Emissions Fall 8%
If we reflect on 2020 and Covid-19, with numerous local and global lockdowns, you might have seen the news headlines that global CO2 levels fell by 8%. Look a bit deeper and you will find that 2019 global emissions of CO2 added 2.5 ppm to the total in the atmosphere, and the 2020 emissions were ‘only’ 2.3 ppm (an 8% reduction on 2019), thanks mainly to COVID-19 effects, taking the total atmospheric level of CO2 to an all-time high of 417 ppm.
Many scientists believe that we need to get the atmosphere level back to a maximum of 350 ppm to stop the warming trend. Most industrial countries have targeted ‘zero carbon’ by 2050, by which time the atmosphere may hold between 440 and 480 ppm CO2.
The 2015 Climate Change Paris Accord stated that the world surface temperature should not exceed 1.50oC above the pre-industrial period. It is currently 1.25oC above this baseline. The rising temperatures are not uniform over the planet; they are rising fastest in the Arctic and Siberian regions.
How did we only reduce annual emissions by 8%? I know in my case I reduced car mileage 2019 v 2020 from ~11,000 miles to ~4,000 miles and a flight in 2019 to Australia and New Zealand (return mileage 21,000) was replaced with a flight to Portugal in 2020 (2,200 miles return).
So… I drove and flew less, but there were still a lot of aircraft flying, including all the cargo planes bringing our food and on-line purchases. Car travel was down, but other road transport continued with a big hike in ‘white van’ deliveries. Many people worked from home, with increased use of typically gas heating, and electricity consumption went up during lockdown due to extra use of lighting, cooking, internet use and broadband. You can start to see how hard it will be to attain global emission targets without enormous government support, scientific innovation, industry willingness to change and the general public’s ability to adopt changes which will in all likelihood be at increased costs.
Artic sea ice