Ladybird Expert series on Climate Change - A Summary
Posted by Guest Blogger on December 04, 2017 at 04:55 PM
Notes on: Climate Change, by Tony Juniper and Emily Shuckburgh
Ladybird Expert series 2017, (52 pages including some illustrations)
Paul Donnelly, August 2017
Paul was a highly respected, committed member of Dublin Friends of the Earth and suddenly passed away in November 2017. He spent much of his time collating information about climate change in order to make the topic more accessible for people. May he rest in peace.
This note sets out to summarise the main points of this recently published book – Climate change – in the Ladybird Expert series. The book sets out to be a simple, plain English guide to the subject, to inform and alert people to the 'wolf at the door' as the foreword describes it and encourage requisite urgent action.
I have prepared this summary of the book to give rapid aclimate changeess to its key points for members and associates of Dublin Friends of the Earth.
The layout of the summary follows that of the book, chapter by chapter using the same titles, and is as far as possible using the same words. I have at times summarised the point made more briefly.
The Earth's climate:
Climate conditions are determined by the atmosphere, oceans, land, ice and the life on our planet acting together with the power of the sun.
Earth's atmosphere is mainly made up of nitrogen and oxygen along with smaller amounts of other gases. These include those commonly referred to as greenhouse gases (GHG) which trap the sun's heat.
The concentrations of GHGs in the atmosphere are increasing, in particular CO2. This is leading to rising temperatures and disruption to the climate.
We are already seeing dramatic impacts: altered weather patterns, reduced snow and ice and a rise in sea levels. These impacts threaten food and water supply, people's health, security and economic activity, as well as wildlife and the natural world. If we don't act immediately our future could be at risk.
A warming world:
Records across the world show that the temperature measured at the Earth's surface has increased substantially over the past century, and especially over the last 50 years. Certain regions, in particular the Arctic, have seen much more warming than others.
Allowing for natural variability from one year to another due to the strength of the sun, the impact of volcanic eruptions and climate cycles such as El Nino, the three decades from 1980 to 2010 all showed record warmth compared with previous decades. Since 2000 the earth's temperature has typically been more than 0.75C warmer than it was 150 years ago and in 2015 it reached 1C warmer.
Other evidence from around the world including warming of the oceans at all levels and reductions in ice and snow cover provide further evidence of global warming.
Melting ice and rising sea levels:
In 2016 and several other recent years, at the end of the summer melt season, the Arctic sea ice has covered less than 2/3 of the area covered at the end of the 20th Century. This will not lead to rising sea levels but change on this scale can alter weather across Europe, Asia and North America.
In addition, as the world has warmed, the water in the oceans has expanded, many mountain glaciers have retreated and the ice sheets in Greenland and Antarctica have shrunk. These changes have raised sea levels.
The effects of sea level rise are felt most acutely when storm surges oclimate changeur in many of the world's developing megacities, as they are located in vulnerable coastal regions. For many, such defences as the London Thames Barrier would be impossible or too expensive to build.
Heatwaves, droughts, floods and storms:
Extreme weather events such as heatwaves, droughts, floods and storms can cause major damage and disruption, with large financial costs and sometimes loss of life.
For example, in 2016 India recorded its then highest-ever temperature of 51C during a heatwave. A severe summer heatwave in Europe in 2003 caused tens of thousands of premature deaths. Since 2000 the UK has experienced devastating flooding on a number of oclimate changeasions and in 2010 in Pakistan floods affected 20 million people.
Across the world extreme weather conditions are leading to temperature and rainfall records being broken, with ever more serious consequences. What were once extreme conditions are starting to become normal. In part, this is because a warmer atmosphere holds more water, leading to more intense rains and increasing flood risk.
Threats to people and where they live:
Threats to food and water supply, human health and national security, and the risk of humanitarian crises are all potentially increased by climate change. Crop yields depend on temperature, rainfall and sunshine. While climate change may be positive for some crops overall it will lead to less secure food supplies.
Water supply across South Asia and China is provided by rivers that depend on regional rain and snowfall as well as meltwater from high glaciers.
Human health can be affected by extreme weather as well as climate change driven factors such as air-pollution and the spread of disease.
Climate change driven changes can lead to existing tensions and may increase the risk of regional conflict and migration. However such climate change can also complicate relief efforts.
Climate change is causing shifts in the environment for wildlife due to changes in temperatures, length and timing of seasons and the availability of water and food.
Rapid climate change outruns the natural capacities of wildlife systems to adapt and poses great challenges, as does loss of habitats, due to agriculture and urbanisation.
Vulnerable animals and plants will die out, for example, polar bears and many sea bound and land species.
This loss of flora and fauna directly threatens us humans as many provide us with medicines and food. The loss will be both material as well as spiritual and cultural.
Impacts on businesses and communities:
Some industries and communities will be particularly vulnerable to effects of climate change and some indeed are already being hit. Examples are insurance companies, food producers and water companies.
Hydroelectric dams are being affected by droughts and reduced river flows. Much of this can lead to shortages of supplies and to higher producer and consumer prices
However many businesses and communities are also seizing opportunities to move to low-carbon sector growth and development.
Climate change in the distant past:
There have been dramatic shifts in the world's climate in the past from frozen states to hothouse conditions.
For the past 2.6m years the world has always had ice at the poles while the climate has oscillated between warm and cold periods in a cycle tied to the natural wobbles of the Earth around the Sun.
The Cold periods most recently reached their greatest ice cover about 22,000 years ago when the sea level was c 130m lower than now and the population of Europe was estimated to have been 130,000 – the size of Cambridge UK today.
Severe and rapid climate changes like those at the end of the last Ice Age probably contributed, along with hunting by humans, to the extinction of large mammals such as the woolly mammoth.
Causes of recent climate disruption:
The scientific evidence is that the dominant cause of the rapid warming of the Earth's climate over the last half century has been the activities of people, which have increased the amount of GHGs in the atmosphere.
More GHGs (C02, CH4, NO, etc.) lead to less solar energy escaping to space which leads to a warming planet.
Fossil fuels such as coal, oil and natural gas were formed from plants and animals that took carbon from the atmosphere over millions of years. As the fossil fuel is burnt that carbon is released rapidly back to the atmosphere mainly as CO2.
Clearance of forests, agriculture (including industrial agriculture) and industrial processes –e.g. cement- have also contributed to increased GHG pollution.
CO2 levels globally are now more than 40% higher than in 1750 at the start of the Industrial Revolution when they were 280ppm. By June 2016 they had reached over 400ppm in Antarctica.
Emissions and the carbon cycle:
Human activities emit 36.4bn tonnes of CO2 into the atmosphere each year. Most is from burning fossil fuel energy and industrial processes (together contributing 33bn tonnes) while the remainder is due to deforestation and other land-use changes.
Carbon dioxide is exchanged continually between the atmosphere, plants and animals through growth, death and decay, and also directly between the atmosphere and ocean. About half is soaked up by land and forests (10.9bn tonnes) and by the oceans (9.5bn tonnes). The rest (16bn tonnes) accumulates in the atmosphere where it is trapped and can't escape.
The world warmed by 4C to 5C since the last Ice Age, as part of the natural cycle tied to changes in the Earth's orbit about the Sun.
If the present accumulation of CO2 continues unchecked, greenhouse warming of similar magnitude might occur by as soon as the end of the century. This scale and speed of change would pose major challenges to both human and natural systems.
Increasing energy demand:
Total global energy use including all domestic and industrial usage has increased twenty-fold (x20) since 1850. This growth was accompanied by a shift from traditional energy sources such as wood, wind and water towards fossil fuels, first coal then oil and natural gas.
Today fossil fuels make up almost 80% of the worlds energy use. Hydropower, wood, biofuels made from plants, and nuclear together account for just under 20% while renewables such as solar and wind represent c 2.5% but are growing rapidly.
Providing clean secure and affordable energy to all is one of the greatest challenges of C21 as population increases and economies grow.
Over 1bn people globally still don't have access to electricity...mostly in Africa and Asia. Some 3bn rely on wood or other solid fuel for cooking or kerosene for lighting, leading to indoor air pollution and millions of deaths per annum. Outdoor pollution from burning coal and oil in power plants, industrial plants or vehicles also causes millions more deaths.
Clearing forests and damaging soils:
Forests take CO2 from the air and store it in trees, plants and soils. When trees are cut down and soil disturbed, much of the CO2 is released back to the atmosphere.
Traditionally deforestation, mainly in temperate regions, was to make room for farming. It not only released carbon but also contributed to the extinction of some animals.
During the last century deforestation accelerated in the tropical regions, including tropical rainforests.
Some are located on areas of peat soils that contain vast quantities of carbon that built up over thousands of years.
When forests are cleared the soil may be damaged by erosion, and agricultural practices can deplete the soil's organic matter, releasing more carbon.
These clearances are continuing mainly to make way for industrial farming, e.g. palm oil, soya and beef.
Deforestation is responsible for at least 1/4 of CO2 pollution over the past 150 years.
Cutting down forests disrupts the water cycle, causing worsening drought in some regions. It also threatens many more animals and plants with extinction.
Past and present changes in CO2:
Today's CO2 levels now vastly exceed those at any point during at least the past 800k years, i.e. into the Early Stone Age. This is known from the atmospheric record in ice cores of the Antarctic ice sheets.
The sediment at the ocean bottom can tell us about the even more distant past. This shows that we are presently emitting CO2 about ten times faster than any natural release in the past 50m years, at least.
Most of today's CO2 pollution will remain in the atmosphere for decades or centuries, and some for '000's of years. Meaning that climate impacts will persist long into the future.
As a further consequence of CO2 pollution the oceans are rapidly becoming more acidic. Comparable rates of ocean acidification have not been seen for many millions of years, perhaps not since about 250m years ago, when the biggest mass extinction of species took place.
About 30% of the CO2 we produce today is soaked up by the oceans. This reduces the amount accumulating in the atmosphere and limits the level of global warming, but at the expense of increasing the acidity of seawater.
Ocean acidification directly affects ecologically vital species (oysters, urchins, corals and various plankton etc.) and may indirectly affect fish populations. A decline in these and other organisms would cause disruption of entire food webs. This would devastate coastal communities and reduce vital food supply.
Corals in particular are severely affected by warming seas (bleaching) and ocean acidification. Combined with other negative factors (storms, water pollution) there is great concern for such wonders as the Great Barrier Reef.
Risk of major environmental changes:
As the world warms there is an increasing risk of irreversible environmental changes or abrupt shocks occurring.
Even modest temperature rise may threaten the vast ice-sheets of Greenland and West Antarctica leading to sea-level rises of several metres thereby transforming global coastlines.
Melting has been seen across more than half of the Greenland ice sheet during recent summers and there is some evidence the collapse of the ice sheet in West Antarctica may already be unstoppable.
Changed rainfall patterns can lead to droughts and forest fires and to forests becoming less dense or even grasslands in some regions. These store less carbon leading to increased warming and on, in turn, to further rainfall changes. This vicious circle could even trigger a rapid dieback of the Amazon rainforest.
Other examples of abrupt changes possible are mega-droughts, monsoon failures and the collapse of the ocean circulation system in the north Atlantic. Another concern is the potential for the massive release of methane from the Arctic permafrost. Methane is many times more powerful as a greenhouse gas than CO2.
Benefits of limiting warming to 1.5C:
In 2016 global average temperature was c 1C warmer than in pre-Industrial times.
Climate change is a major concern of small island states – Maldives, Tuvalu etc., which are only a few metres above the ocean.
During the extended warm period about 400k years ago a large fraction of Greenland was ice free and sea levels rose slowly over centuries to more than 6 metres higher than today. While local conditions influence the ice sheets, at that time the global average temperature was perhaps only slighter warmer than today.... a warning, perhaps, for us.
In the 2015 Paris Agreement the world's governments committed to hold the global temperature to well below 2C above pre-industrial levels and to pursue efforts to limit warming to 1.5C by reducing and eventually eliminating GHG pollution.
Such action would not only reduce the overall risks from climate change but provide a range of other benefits.
The scale and urgency of pollution cuts:
If the Paris objectives are to be met then CO2 emissions will need to be eliminated in net terms by about 2050. We need to act urgently.
The amount of carbon dioxide we can release before dangerous levels of warming are reached can be seen as a Carbon Budget.
The budget of CO2 emissions to stay below 2C of warming is 3 thousand billion tonnes in total. But we have already emitted 2 thousand billion tonnes since 1870. This leaves a remaining budget of 1 thousand billion tonnes.
At the current annual emissions level of 40bn tonnes we are on course to use up the 2C Carbon Budget within the next 20-30 years, before 2050.
The 1.5C budget limit would be reached even sooner.
Moreover, even if we eliminate emissions, elevated temperatures will persist and some climate changes will continue to develop for many hundreds of years as, for instance, the deep oceans slowly warm, the ice sheets shrink and sea levels rise.
To cut out GHGs we must work to stop our reliance on fossil energy.
We must shift to renewable sources e.g. wind, sun, plants, tides waves, waste to energy technologies and hot rocks underground.
In tandem, we need to develop better electricity storage technologies including new batteries. This will allow us to shift our transportation to electric vehicles.
Technologies must also be developed and adopted to capture CO2 from power stations running on fossil fuels and store it underground.
An additional element to cutting emissions quickly is improvements in energy efficiency in all uses from industry to home heating to transportation.
By later this century we will need to have found new ways of removing large amounts of CO2 from the atmosphere without damaging side effects – especially if we are to limit average temperatures to a 1.5C increase.
Stopping deforestation, protecting natural forests, and restoring some of the forests that have already been lost – including on degraded land unsuitable for farming- will be a major part of the solution for reducing GHG pollution and limiting climate change.
This is not easy but when ways are found to make these forests valued it will be possible to progress. Increasingly countries are realising the contribution that their tropical rainforests make to their development. They help rainfall and support clean water for farming and rivers that provide hydroelectric power. They also help reduce flooding and protect soils. These services are essential for maintaining secure supplies of food and water. As well as helping to reduce CO2 pollution.
In West Africa cocoa farmers are being assisted to raise crop yields so they can increase their income without cutting down more forest. This includes switching to agroforestry where crops and trees are grown together.
Food and farming solutions:
Farming can be part of the solution, if food producers switch to methods which build up carbon levels in soils. Soils -especially those with a high proportion of organic matter- are important sinks of carbon.
Organic matter is made up of once-living material e.g. plant leaves and roots which are gradually broken down by tiny organisms in the soil releasing nutrients to enable crops to grow without the need for manufactured fertilisers.
Increasing the amount of organic matter in the soil can best be achieved by using crop rotations and by mixed crop and livestock farming. These and other techniques such as applying composted animal and plant wastes and adding charcoal reduce manufactured fertiliser use. Production of the latter uses fossil fuel energy and releases high levels of nitrous oxide, a powerful GHG.
Good quality soils also hold more water, protecting plants against drought, making farming more resilient as the climate changes.
Emission can also be reduced by cutting food waste and through consumption of less but better quality meat and dairy products.
Our planet and its ecosystems run through cycles and loops e.g. the water cycle and the carbon cycle. Everything is recycled and reused; in nature there is no waste.
Not so with human activities. We take resources, make products, use them and often dispose of them in waste that goes into the land, the atmosphere and the oceans, without recapturing the resources that goes into making them.
This not only wastes the Earth's limited resources but also uses up energy and leads to higher pollution than if we did things in a more natural, circular way.
By harnessing new technologies, designing products differently and planning for a zero-waste future we could create a 'circular economy'. This would copy nature and see what is now waste, instead as a resource for future valuable use. Some companies/sectors are already turning this into reality e.g. manufacturing fuels from paper-making process residues.
Meeting the challenge of climate change:
Climate change is a truly global challenge which no one country on its own can solve. In 2015 nearly all the world's countries pledged in the Paris Agreement to limit future warming through drastic cuts in fossil energy use and also by measures such as conserving and restoring forests and maintaining the health of our soils.
Most countries pledged certain targets for reduced emissions. However the pledged amounts are not yet enough to keep temperatures below 2C let alone 1.5C. But there is a review mechanism for strengthening them.
The elimination of GHG emissions over the next few decades will limit future climate change but some climate impacts will still be felt around the world (due to cumulative emissions to date). These will have impacts on ecosystems, peoples and livelihoods. So the Paris Agreement envisages the need to adapt to some climate change (and agreed for an annual fund of $100bn to help less developed countries or those most affected).
New opportunities and improved quality of life:
Tackling climate change provides opportunities for new sectors/products leading to new jobs. It may also improve the quality of peoples' lives....less pollution of air and water, less forest cutting for fuel, cleaner water.
Governments can help accelerate this positive change by providing incentives to reduce emissions, preserve and grow more forests etc. For example instead of subsidising fossil energy, they should require polluters to pay for emissions.
Over the centuries our demands on nature have expanded massively but there is still only one Earth. Our impact on it grows as our population grows and we consume more and more of the Earth's vital resources. We have been mistreating the Planet and abusing its natural systems. It is time to act before it’s too late for our human civilisation.
Paul Donnelly’s personal addition:
Some Important Data since 1850: Derived from this book or from Tony Juniper's larger book - What's happening to our Planet? (2016)
- Global Population: A sixfold increase ( ie x 6 to 7.3bn now) [ x3 since 1950]
- Global GDP : A one hundredfold increase (ie x 100 ) [ x 10 since 1950]
- Global Energy Use: a twenty fold increase ( ie x 20) [ x5 since 1950]
- Global Surface Temperature: Up 1C since 1850. Faster rise recently.
- Global Sea Level: Up over 20cm since 1850. Faster rise recently.
- Tropical Forest Area: Down by over 25% since 1850. Decline continuing at same rate since 1950.
And some additional Facts:
- CO2 levels have increased by over 40% since 1850 after being stable for 800k years. Faster rise recently.
- Fresh water use up five fold since 1950
- Grain production up four fold since 1950
- More than half of global population now in towns or cities. Growth rate increasing.
- 800m people globally are malnourished. Some decline recently but food resources under increasing pressure.
- Species extinctions since 1950 up ten- fold (matching GDP growth)
- The dramatic increase in food production globally since 1950 has been due to the matching growth in the use of manufactured fertilisers. This in turn has led to significant negative environmental effects.
- The increase in global food production has also relied on pesticides the use of which has increased 50- fold since 1950. As with nitrate fertilisers the environmental cost has been significant.
- One third of all land is at risk of desertification
- Sea Fish capture increased by four-fold since 1950's [but levelled out by 1990s]. Many stocks under threat.
- Ten thousand years ago human and their animals accounted for 0.1% of the total animal & bird biomass. Today they account for 99.9% of it.
- Over one-third of the Earth's land is now used for farming. However three-quarters of that is used for meat or dairying. Even of the one-quarter used for crops a high proportion is fed to livestock.