Urgent and world-wide action is required to make transition to clean energy. Business as usual will bring catastrophic environmenal and ecological changes for future generations.
UN warns that world risks becoming 'uninhabitable hell' for millions unless leaders take climate action (October 13, 2020)
In a recent talk, I had discussed the impact of global warming and climate change on our planet. Dire as they are, it is difficult to feel hopeful that the nations of the world will act in time to mitigate the worst effects of climate change. Doing nothing will simply make the problems worse with catastrophic consequences - we need to do our best to limit climate change. The goal (2⁰C rise) and aspiration (limit the rise to 1.5⁰C) of the 2015 Paris Accord require that by the year 2050, CO2 net emissions are brought down to zero (Net Zero) from the current levels of about 36 gigatons per year and significantly reduce the emission of methane and nitrous oxide . Five years on, the progress made has been disappointing; emissions have continued to increase and the scientific opinion is converging to the view that by 2100, global warming will be in the region of 3⁰C - a serious and frightening prospect. The following slides summarize the situation:
In their mammoth 2019 report (630 pages), IPCC have looked at
various pathways for limiting global warming to 1.5⁰C.
Essentially, there is a
lot of CO2 in the atmosphere already (411 parts per million - October 2020) and we continue to add more CO2 every day
(over the past decade CO2 levels have increased by 24 parts per million or 5.8%). All pathways require that we start to cut down CO2
emission now or in the very near future with Net Zero emissions by around 2050,
and also remove CO2 from the atmosphere at a rate depending on how soon and how fast we cut down emissions. The later we start,
the more severe the reductions will have to be. In the next
slide, I show one of the pathways that IPCC have analysed - these
are theoretical possibilities and assume certain modest technological developments
will be forthcoming. Please read the report when you have a week to spare.
1. Energy demand is continuing to increase. Our standard of living depends directly on the amount of energy we use. In rich countries, most people will not agree to sacrifice the way they live. In developing countries, people aspire to live 'better' and that translates into increased energy consumption. Additionally, population is expected to be greater than 10 billion by 2100, up from 7.8 billion now. Politically, national governments find it difficult to plan for any reduction in energy consumption. Also most governments work on debt funded economic models, underpinned by perpetual growth - more consumption is encouraged by businesses.
2. Fossil
Fuels produce most of the energy just now: About 80% of the
global energy production uses fossil fuels which emit copious amount of CO2
into the atmosphere. Renewables (solar & wind) generate a meagre 2% of the global energy. With vested interests preventing change, the task of
replacing fossil fuels by renewable energy is non-trivial.
Fossil fuels also produce 64% of the electricity
with hydroelectric, nuclear and renewables (solar and wind) making up the rest.
It may be that electricity
generation by renewables (mostly solar and wind) can be ramped up to such an
extent that we can have near 100% decarbonised electricity. A factor of 10
increase in solar and wind installations will be required to replace fossil
fuels in current electricity generation. However,
note that electricity is less than 20% of the total energy needs of the world
which are largely met by fossil fuel combustion; solar and wind currently
supply only about 2% of the total energy needs. Nuclear and hydro-electric energy generation capacity is not expected to increase much and likely to stay near current level for the foreseeable future.
Another important reason for not burning fossil
fuels is that they produce large amounts of polluting gases and particulate
matter - the air pollution is estimated to cause 7 million premature
deaths each year.
3. Harder to Abate Sectors: Besides meeting
current electricity demand, renewable energy can also replace fossil fuels in
light transport (electric cars), much of agricultural machinery, space heating
and light-weight industrial plants.
Another hard to abate sector is agriculture (AFOLU), particularly animal farming where cattle numbers have increased extremely rapidly. They generate large amounts of methane (enteric fermentation). Globally, ruminant livestock produce about 3.3 GT CO2 equivalent of enteric methane emissions. This contribution is expected to increase in future years. See also where it is estimated that humans and farm animals exhale in excess of 8.5 GT CO2 per year - this is a large contribution to overall emissions and difficult to reduce.
What Are Our Options?
1. Energy efficiency: We can drastically reduce the energy we use (increase energy efficiency -
this means that we cut down the amount of energy to perform a task). It is also
important to make serious move to a circular economy with zero waste. It
is estimated that energy
efficiency gains can reduce energy requirements significantly and it is
possible to keep the energy demand in 2050 at 2018 levels or lower! (See
Slide below) This will certainly help limit CO2 emissions and
must be seriously implemented. However, as long as fossil fuels are in
use, CO2 concentration in the atmosphere will continue to increase.
Energy efficiency on a personal level - keeping the central heating
lower by 1 or 2⁰C, switching off lights in unoccupied
rooms, walking or cycling instead of using car for short distance journeys -
can be very effective. On a community and national level, much can be
done to help - for example, heat pumps provide a factor of three savings in energy.
Most buildings could be heated or cooled using heat pumps with a reduction of
up to 70% in CO2 emissions from this sector. The ultimate goal will be to
run the heat pumps on renewable energy and completely eliminate CO2 emissions
from space heating and cooling.
2. Renewable energy: Massively expand existing renewable energy generation to replace fossil fuels. Remember, nuclear and hydro energy have extremely limited growth potential. Solar and wind energy is already cheaper than fossil fuel energy and further price reductions are expected. Over the next 10 years, it will make good economic sense to replace much of fossil fuel use (wherever possible) by expanding renewable energy generation.
Currently, most of the 75 million tonnes (in 2019) of hydrogen is
obtained from steam reforming of natural gas (grey hydrogen), and is used in
fertilizers, refining petrochemicals and in the production of ammonia and
methanol in the chemical industry. Hydrogen production using
fossil fuel energy added 0.85 GT of CO2 to the atmosphere in 2019.
It is expected that by 2050, the emission free production of 500 million tonnes of green and blue hydrogen will displace 1400 Mtoe (million tonnes of oil equivalent) of fossil fuels to generate 17000 TWh of energy. (1 kg of hydrogen generates 33 kWh; 1 kWh = 1 unit of electricity).
4. Biomass energy: Biomass is any organic, biological or plant matter
(excluding fossil fuels) which can be converted into a usable energy source;
for example, trees, plants, wood, grasses, organic wastes etc. In
biomass, energy is stored in the form of carbohydrates (cellulose, starch and
sugar) that are produced in the photosynthesis of solar energy by plants. Biomass is a renewable energy
source; however, as is often claimed, it is debatable if biomass is net
emission free (carbon neutral); or if biomass with carbon capture, use and
storage (CCUS) is a negative emission energy source.
Essentially, plants use atmospheric CO2 to make carbohydrates – the CO2
is released back to the atmosphere when biomass is used to generate
energy. New plant growth will repeat this process – renewable energy
source. However, how land is used to cultivate plants for bioenergy is
critical for biomass to be carbon neutral. Additionally, the processing
of biomass to synthesize biofuels requires energy that is currently supplied by
fossil fuels. This makes the lifecycle biomass energy a net GHG
emitter. A good example is the synthesis of biofuels from sugarcane
or grains which are generally grown on crop lands or by clearing forests. This
not only removes carbon sinks from the environment (creates biofuel
carbon debt) but also adversely affects land availability for agriculture.
In contrast, biofuels made from waste biomass or from biomass
grown on degraded and abandoned agricultural lands planted with
perennials incur little or no carbon debt and can offer
immediate and sustained GHG advantages.
Notice that used
cooking oil is much better than other biomass because it does not require any
land use.
5. Carbon capture: Capturing CO2 produced in industrial plants using fossils is an expensive process and significantly reduces their energy production efficiency. Also, CO2 produced by diffused sources like automobiles, planes, farming etc. is very difficult to capture at source. This does not affect the CO2 already present in the atmosphere. As we have discussed above, some CO2 emissions, like CO2 exhaled by humans and farm animals, will be impossible to abate and it will be important to capture CO2 from the atmosphere to achieve net-zero.
We need to develop carbon
capture, use and storage technology with aim to remove, by the year 2050, about
10 gigatonnes of CO2 from the atmosphere per year. 
The current cost of DAC is of the order
of $400 per captured tonne of CO2. To capture 10 GT CO2 per year will
cost 4 trillion dollars! DAC is a new technology and it is expected that
cost will substantially come down in the future.
Reforestation: Trees, through photosynthesis absorb CO2 from the atmosphere and store it as wood. Planting new trees is a great idea for helping to reduce CO2 atmospheric concentration. 1t.org mission is to plant one trillion trees by 2030 to combat the worst effects of climate change. However, one notes that trees take time to mature and the process is too slow to meet the goal of Net-Zero by 2050. Reforestation is a great idea and will help in reducing CO2 conecentrations.
BioEnergy with Carbon Capture and Storage (BECCS): The idea is to grow crops that soak up CO2 and then burn them to produce energy but capture and store all the CO2 that is produced. To meet the Net-Zero goal, we shall need to deploy huge amounts of land which would affect agricultural production at a time when global population is increasing. It is estimated that BECCS could cause an increase in food prices by 3 to 5 times by 2050 - an unacceptable burden on the world's poor nations.
6. Transition to plant protein: Make a rapid transition from farm
based meat/protein to plant protein. At present, there is no other way to
reduce the enteric emissions from cattle whose numbers have been increasing
rapidly over the past 50 years. Switching from animal to plant protein
will also directly reduce the emissions from animal farming.
Nothing will benefit health and increase chances
for survival of life on Earth as much as the evolution to a vegetarian
diet. ...Albert Einstein (quoted)
AFOLU sector is a big emitter of GHGs and rather difficult to abate. A 2020 report by McKinsey has analysed the options in detail and the slide summarizes their findings:
Where do we go from here?
The above list is a big ask but is doable - given the will and co-operation of the nations of the world. Renewable electricity is already competitive with fossil fuels generated electricity despite the 5+ trillion dollars of subsidy that fossil fuel industry enjoys. Much of the basic technology exists, and can easily be developed further to accomplish full decarbonisation of the industry. The time window to start is very narrow - may be one or two years. We have known about climate crisis for decades but have failed to act. Action at global level is required and it is difficult to be optimistic that we shall be able to limit global warming to 1.5⁰C or even to 2⁰C.
Only six countries have legally binding position to achieve
net-zero (click here for the list + China) while some
important polluters (e.g. the USA) have effectively given up on it. Despite
announcing their goal to reach net-zero by 2060, China is going ahead with the
building of new coal power stations - it is not clear how serious these
commitments are.
India expects to increase its coal-fired electricity generation by 22% over the next three years. Such facilities have an operational life span of 20 to 40 years. Demand of electricity is increasing rapidly in India and one can be sympathetic to the need to increase generation capacity quickly. This sort of situation just highlights the result of failure to act in time. With proper R&D support renewable energy could have been developed quicker and is the obvious choice for generating additional power - particularly in a country like India where plentiful solar energy is available.
Concluding Remarks: It is important to meet the net-zero target. This is scientifically/technologically possible but requires serious effort by all countries of the world. The cost of abatement may be as much as 2% of global GDP (~3 trillion dollars per year); this is affordable. In absence of effective action, soon it may be difficult to meet the 1.5⁰C or 2⁰C target but that will make the world a much less pleasant place to live - this is the only planet we have.
Thanks for reading. Any comments will be appreciated. Please pass on the link to this blog to your friends and family.
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