So, who is responsible for these vast changes in our planet's systems? The problem is extremely complex, but there are undeniable culprits. Let's take a look at the primary contributors to global Carbon Dioxide emissions.
This famous curve, called the Keeling Curve, shows Carbon Dioxide concentrations in the atmosphere over time. This data has been collected at the Mauna Loa Observatory in Hawaii since 1958, and it shows that CO₂ concentrations fluctuate seasonally but are rising steadily with time. This is one of the fundamental datasets in climate science and was monumental in the discovery of mankind's role in climate change. CO₂ is a Greenhouse Gas (GHG), which acts as an insulating blanket over the planet. The more CO₂ there is in the atmosphere, the more heat is retained. That is, as CO₂ concentrations increase, global temperatures increase. There has been no slowing of CO₂ emissions since the Industrial Revolution began.¹
Here we see global temperature anomalies since 1880. Anomalies are compared to the average global temperature over the 20th century. Thus we see that temperatures are rising on Earth, and like CO₂ concentrations, there has been no indication of temperatures leveling out or even increasing more slowly. Temperature increases are accelerating with time.²
This graph shows cumulative changes in sea level for the world’s oceans since 1880. It shows average absolute sea level change, which refers to the height of the ocean surface, regardless of whether nearby land is rising or falling. As can be seen, sea levels have been steadily rising over the past 100+ years. There are a three main reasons why sea levels are rising: 1. Warming temperatures cause water to become less dense and thus expand, 2. Ice sheets melt faster than new snow and ice form, and 3. Glaciers melting, as shown in the next graph. As sea levels continue to rise, coastal regions will experience more flooding and ultimately succumb to the ocean, and there will likely be a mass exodus of people living in coastal cities towards inland areas.³
This graph shows change in mass balance of a set of “reference” glaciers worldwide beginning in 1945. "Mass balance" refers to the gain and loss of mass (ice) from the glacier. Negative values indicate a net loss of ice and snow compared with the base year of 1945. Note that the entire dataset is negative. Measurements are in meters of water equivalent, which represent changes in the average thickness of a glacier. In short, this dataset reveals that the world's glaciers are melting at an accelerating rate.⁴
So, who is responsible for these vast changes in our planet's systems? The problem is extremely complex, but there are undeniable culprits. Let's take a look at the primary contributors to global Carbon Dioxide emissions.
This graph shows the percentage share of emissions by different sectors in the world. Electricity and heat production has taken up nearly half of all emissions in the 21st century. This is why transitioning to renewable, emission-free forms of energy is imperative for our planet's health and survival.
Carbon Dioxide is emitted from the burning of fossil fuels. Fossil fuels are coal, oil, and gas. As consumption of these fuel sources continue to accelerate, CO₂ emissions also continue to accelerate. If our planet is to avoid unprecedented ecological collapse in the coming decades, it is imperative that our world transitions to more renewable sources of energy, like solar and wind.
¹ C. D. Keeling, S. C. Piper, R. B. Bacastow, M. Wahlen, T. P. Whorf, M. Heimann, and
H. A. Meijer, Exchanges of atmospheric CO2 and 13CO2 with the terrestrial biosphere and
oceans from 1978 to 2000. I. Global aspects, SIO Reference Series, No. 01-06, Scripps
Institution of Oceanography, San Diego, 88 pages, 2001. Data
² NOAA National Climatic Data Center (NCDC), global component of Climate at a Glance (GCAG). Data
³ Church, J. A. and N.J. White (2011), Sea-level rise from the late 19th to the early 21st Century. Surveys in Geophysics, doi:10.1007/s10712-011-9119-1. Data
⁴ WGMS (World Glacier Monitoring Service). 2015 update to data originally published in: WGMS. 2013. Glacier mass balance bulletin no. 12 (2010–2011). Zemp, M., S.U. Nussbaumer, K. Naegeli, I. Gärtner-Roer, F. Paul, M. Hoelzle, and W. Haeberli (eds.). ICSU (WDS)/IUGG (IACS)/UNEP/UNESCO/WMO. Zurich, Switzerland: World Glacier Monitoring Service. http://wgms.ch/downloads/wgms_2013_gmbb12.pdf. Data
⁵World Development Indicators, The World Bank. Data
⁶Boden, T.A., G. Marland, and R.J. Andres. 2017. Global, Regional, and National Fossil-Fuel CO2 Emissions. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A. doi 10.3334/CDIAC/00001_V2017 Data