Increase in greenhouse gas emissions

Human activities have increased the amount of greenhouse gas emissions in the atmosphere. Since the invention of the steam engine in the begining of the industrial revolution, humanity has been burning fossil fuel for energy generation, energy that’s being used in every economic sector.

The Sankey diagram above shows the system boundaries of the industry sector and demonstrates how global anthropogenic emissions in 2010 arose from the chain of technologies and systems required to deliver final services triggered by human demands. The width of each line is proportional to GHG emissions released, and the sum of these widths along any vertical slice through the diagram is the same, representing all emissions in 2010 (Bajželj et al., 2013).
Source: IPCC

The total anthropogenic greenhouse gas emissions (gigatonne of CO2- equivalent per year, GtCO2-eq/yr) from economic sectors in 2010.The circle shows the shares of direct greenhouse emissions (in % of total anthropogenic GHG emissions) from five economic sectors in 2010. The pull-out shows how shares of indirect CO2 emissions (in % of total anthropogenic GHG emissions) from electricity and heat production are attributed to sectors of final energy use. ‘Other energy’ refers to all GHG emission sources in the energy sector, other than electricity and heat production. The emission data on agriculture, forestry and other land use (AFOLU) includes land-based CO2 emissions from forest fires, peat fires and peat decay that approximate to net CO2 flux from the sub-sectors of forestry and other land use (FOLU). Emissions are converted into CO2-equivalents based on 100-year Global Warming Potential (GWP100)
Source: IPCC 2014(AR5)

Global inequalities in CO₂ emissions

The following chart is a distribution of carbon dioxide emitted by country/region in 2017.

x axis – number of people (in billions) on the planet in 2017
y axis – CO2 emission(in tonnes) per person in 2017

The warming potential of methane

Even though the amount of methane in the atmosphere is small in comparison to carbon dioxide, this greenhouse gas traps 84 times more heat than carbon dioxide over a 20 year period. “Since the Industrial Revolution, methane concentrations in the atmosphere have more than doubled, and about 20% of the warming the planet has experienced can be attributed to the gas.” The main sources of methane emissions into the atmosphere are human activities like cattle grazing, leaks from oil and gas drilling sites and also landfills and sewage treatment centers. Keeping methane emissions in check is important in order to reduce the global heating in the next decades.

Reducing carbon sinks

Natural areas like peat bogs, forestry, oceans and wetlands are capturing and storing carbon from the atmosphere. Human activities like over-exploitation and deforestation has reduced the area of these environments that act as carbon sinks, thus reducing their capacity to store carbon.