World’s leaders are gathering in GlasgowTo tighten their emission-curbing obligations with a view towards achieving net zero emissions by 2050. Three major documents provide the essential science that will guide their discussions.
The first – the 6th assessment of the United Nations’ Intergovernmental Panel on Climate Change (IPCC) published on August 9 – expresses greater scientific certainty than previous reports that human activity is responsible for global warming. “It is unequivocal that human influence has warmed the atmosphere, ocean and land,” it states.
This claim is supported by several key findings. The 2019 atmospheric CO2 (CO2) concentrations were greater than ever in at least two millions years and the methane (CH4) concentrations were higher that at any point in the past 800,000.
These concentrations “far exceed … the natural multi-millennial changes between glacial and interglacial periods over at least the past 800,000 years”, the report says.
These greenhouse gas concentrations have increased in the past 1750, which is the beginning of the Industrial Revolution in Europe. Atmospheric CO2 concentrations have increased by 47 percent to reach 410 parts/million. Over the same time, methane concentrations (1.866 parts per billion), have increased by 156 percent. This proves that greenhouse gas concentrations can be attributed to human activities, according to the IPCC.
Recent weather data supports the claim that global warming is caused by humanity. According to the IPCC, each decade since 1850 has been steadily warmer than the previous. If compared to the second half the 19th century, the global surface temperature was 1.09 degrees Celsius (1.96 Fahrenheit) higher over the past decade.
Rising sea levels can also be a sign of warming. The global average sea level increased by 20cm (7.9 inches) between 1901 and 2018, says the IPCC’s report. It is “virtually certain” that human-caused CO2 emissions are the main driver of the current global acidification of the surface open ocean.
What happens if leaders fail make promises and don’t follow through? Five scenarios of emissions were modelled by the IPCC.
- If the world emulates the European Union’s commitment to halving emissions by 2030 and eliminating them altogether by 2050, possibly extracting some CO2 from the atmosphere thereafter, global average temperatures by 2100 will be roughly 1.4C (2.5F) higher than in 1850 – only slightly higher than today’s.
- If emissions remain at today’s levels, the global mean temperature by 2100 will be closer to 2C (3.6F) higher than in 1850.
- An intermediate model indicates a continuing but not rapid change in emissions, leading to a global temperature increase of 2.7% (4.86F) by 20100.
- In the highest two models, if emissions roughly double relative to today’s, global mean temperatures by 2100 rise by between 3.6C (6.48F) and 5.7C (10.26F).
How likely is it that the world will adopt a policy of net zero emissions by 2050, then?
‘Low emissions revolution’
The latest version World Energy Outlook 2021, the second crucial document, the International Energy Agency (IEA) does not see a path to net zero emissions by 2050 under the world’s announced policies, and even less so under current actions undertaken to meet those policy objectives.
Instead, it predicts an increase in CO2 emissions from 31.5gigatonnes in 2020 to 36Gt in 2030. This is because while coal use is declining globally, oil & gas are increasing their share.
The IEA’s assessment of the oil industry for this year included the following: The IEA forecasts that oil consumption will rebound within two years from the COVID-19 slump and reach 104.1 millions barrels per day by 2026. This is an increase of 4.4mb/d relative 2019
This rebound scenario is already being realized. The world’s emissions have risen so much this year, two-thirds of the emissions cuts achieved during the 2020 COVID-19 pandemic have been eliminated.
“A low emissions revolution is long overdue,” the IEA says.
The revolution is not yet here. According to the IEA the government is underfinancing the clean-energy revolution by providing only one-third the money they should be spending in order to reach a net zero scenario.
Under current or planned infrastructure changes, called the Stated Policies Scenario, almost all the growth in energy demand by 2050 is met by low emissions sources, “but that leaves annual emissions at around current levels”, the report says, because not enough progress is being made in other sectors such as construction and transport.
“As a result, global average temperatures are still rising when they hit 2.6°C above pre-industrial levels in 2100.”
To meet their pledges, both the government and the private sector must double clean energy financing and investment over the next decade. This is the more noble Announced Policy Scenario.
“The successful pursuit of all announced pledges means that global energy-related CO2 emissions fall by 40% over the period to 2050 … The global average temperature rise in 2100 is held to around 2.1°C above pre-industrial levels in 2100,” says the report.
However, even this is not enough. In May this year, the IEA published the first comprehensive study of what the world would have to do to reach net-zero emissions by 2050, a goal the IPCC finds absolutely necessary to maintain global warming below 1.5˚C.
Record level of renewables
The third document is Net Zero by 2050A Roadmap for Global Energy Sector. The required scenario includes halting all investments in fossil fuel energy projects, halting all sales of internal combustion engines cars by 2035, and zero emissions in the electricity industry by 2040.
This pledge is crucial because the electricity sector accounts almost three quarters of global greenhouse gas emissions. In order to achieve it, however, the world would have to install four times last year’s record level of renewable energy generating capacity each year. This, the IEA says, is “equivalent to installing the world’s current largest solar park roughly every day”.
By 2030, global energy investment would need to reach $5 trillion per year.
Even with all this, the IEA still believes that current technologies are not sufficient to meet rising energy demands and emission reduction targets for 2030. To cover approximately half of the emission reductions required after 2030, it is necessary to develop new technologies.
Clearly, the world is not yet on track to meet net-zero criteria by 2050, but the scientific and economic research available to policymakers at the COP26 in Glasgow is now greater than ever before – and so is the political pressure.