year in the 1990s, accelerated to 2.9% per year in the 2000s, but have returned to a
slower growth rate of 0.9% per year since 2010 with a more pronounced slowdown
from 2014 to 2016 [15].
Over the last decade (2009–2018), 42% of fossil CO 2 emissions were from coal,
34% from oil, 19% from natural gas, and the remaining 5% from cement and other
smaller sources. From the perspective of the use of these fossil fuels, 45% of fossil
CO 2 emissions come from the energy sector, dominated by electricity and heat
production, while industry sectors, such as metals production, chemicals and
manufacturing, cover 22% of global emissions, land transport combined with
national shipping and aviation contribute 20% of global emissions, international
shipping and aviation 40 add another 3.7%, and the remaining 10% is from
buildings, agriculture, fishing and other sectors [15].
Despite modest declines in emissions in the USA and the European Union over
the last decade, the growth in emissions in China, India and most developing
countries has dominated global emission trends over the last 20 years. Main
determinants for these trends [16] include the increasing use of coal in developing
countries, pushing by increasing built infrastructures, and the increasing use of gas
in developed countries, counterbalanced by low-carbon energy options, pushed by
public policies. The share of fossil fuel in global primary energy consumption has
remained steady since 1990.
China has become the largest CO 2 emitter in the world and presently accounts
for 30% of global emissions. Major drivers of energy-related CO 2 emissions in
China from 1978 when the reform and opening-up policy was launched include
primarily economic growth (176%) followed by population growth (16%), while
the effects of energy intensity (−79%) and carbon intensity (−13%) slowed the
growth of carbon emissions over most of this period [17]. Energy intensity stands
for the amount of energy per unit of GDP, while carbon intensity refers to the
emissions per unit of energy consumed. Energy efficiency may condition the former
while the share of renewables determines the later.
On the opposite trend, displacement of fossil fuels by renewable energy and
decreases in energy use explain the decreasing CO 2 emissions in a group of 18
developed economies that have decarbonized over the period 2005–2015 [18].
Correlation analysis suggested that policies on renewable energy are supporting
emissions reductions and displacing fossil fuels, while policies on energy efficiency
are supporting lower energy use in those 18 countries.
Regarding the CO 2 emissions from land use change, there is no clear trend over
the last decade, though the data are very uncertain [13]. The terrestrial CO 2 sink
increased from 1.3±0.4 GtC yr−1 in the 1960s to 3.2±0.7 GtC yr−1 during 2009–
2018, with important interannual variations, generally showing a decreased land
sink during El Niño events. The total atmosphere-to-land carbon fluxes increased
from a 0.2±0.8 GtC yr−1 source in the 1960s to a 1.7±0.9 GtC yr−1 sink during
2009–2018, meaning the biosphere increased its ability to sequester CO 2 from the
atmosphere in that time period.
According to IPCC (2018), there is a high confidence that global warming is
expected to surpass 1.5°C above pre-industrial levels with the expected GHG
Carbon Economy and Carbon Footprint
11
slower growth rate of 0.9% per year since 2010 with a more pronounced slowdown
from 2014 to 2016 [15].
Over the last decade (2009–2018), 42% of fossil CO 2 emissions were from coal,
34% from oil, 19% from natural gas, and the remaining 5% from cement and other
smaller sources. From the perspective of the use of these fossil fuels, 45% of fossil
CO 2 emissions come from the energy sector, dominated by electricity and heat
production, while industry sectors, such as metals production, chemicals and
manufacturing, cover 22% of global emissions, land transport combined with
national shipping and aviation contribute 20% of global emissions, international
shipping and aviation 40 add another 3.7%, and the remaining 10% is from
buildings, agriculture, fishing and other sectors [15].
Despite modest declines in emissions in the USA and the European Union over
the last decade, the growth in emissions in China, India and most developing
countries has dominated global emission trends over the last 20 years. Main
determinants for these trends [16] include the increasing use of coal in developing
countries, pushing by increasing built infrastructures, and the increasing use of gas
in developed countries, counterbalanced by low-carbon energy options, pushed by
public policies. The share of fossil fuel in global primary energy consumption has
remained steady since 1990.
China has become the largest CO 2 emitter in the world and presently accounts
for 30% of global emissions. Major drivers of energy-related CO 2 emissions in
China from 1978 when the reform and opening-up policy was launched include
primarily economic growth (176%) followed by population growth (16%), while
the effects of energy intensity (−79%) and carbon intensity (−13%) slowed the
growth of carbon emissions over most of this period [17]. Energy intensity stands
for the amount of energy per unit of GDP, while carbon intensity refers to the
emissions per unit of energy consumed. Energy efficiency may condition the former
while the share of renewables determines the later.
On the opposite trend, displacement of fossil fuels by renewable energy and
decreases in energy use explain the decreasing CO 2 emissions in a group of 18
developed economies that have decarbonized over the period 2005–2015 [18].
Correlation analysis suggested that policies on renewable energy are supporting
emissions reductions and displacing fossil fuels, while policies on energy efficiency
are supporting lower energy use in those 18 countries.
Regarding the CO 2 emissions from land use change, there is no clear trend over
the last decade, though the data are very uncertain [13]. The terrestrial CO 2 sink
increased from 1.3±0.4 GtC yr−1 in the 1960s to 3.2±0.7 GtC yr−1 during 2009–
2018, with important interannual variations, generally showing a decreased land
sink during El Niño events. The total atmosphere-to-land carbon fluxes increased
from a 0.2±0.8 GtC yr−1 source in the 1960s to a 1.7±0.9 GtC yr−1 sink during
2009–2018, meaning the biosphere increased its ability to sequester CO 2 from the
atmosphere in that time period.
According to IPCC (2018), there is a high confidence that global warming is
expected to surpass 1.5°C above pre-industrial levels with the expected GHG
Carbon Economy and Carbon Footprint
11