Special Topics in Environmental Management

Climate Changes are Unprecedented and Undeniable, Reports the IPCC

Unique climate changes have been reported across every region in the world and in the entire climate system, according to the latest Intergovernmental Panel on Climate Change (IPCC) Report, released on August 9, 2021.

“Many of the changes observed in the climate are unprecedented in thousands, if not hundreds of thousands of years, and some of the changes already set in motion—such as continued sea level rise—are irreversible over hundreds to thousands of years,” according to the report issued by the IPCC Working Group I (WGI), which marks the first installment of the IPCC’s Sixth Assessment Report (AR6), which will be completed in 2022.

“However, strong and sustained reductions in emissions of carbon dioxide (CO2) and other greenhouse gases would limit climate change. While benefits for air quality would come quickly, it could take 20-30 years to see global temperatures stabilize …,” the report notes.

Without immediate large-scale reductions of greenhouse gas (GHG) emissions, limiting warming to “close to 1.5°C (34.7°F) or even 2°C (35.6°F) will be beyond reach,” states the report.

“The report shows that emissions of greenhouse gases from human activities are responsible for approximately 1.1°C of warming since 1850-1900, and finds that averaged over the next 20 years, global temperature is expected to reach or exceed 1.5°C of warming,” according to the IPCC. “This assessment is based on improved observational datasets to assess historical warming, as well progress in scientific understanding of the response of the climate system to human-caused [GHG] emissions.”

“This report is a reality check,” says IPCC WGI Co-Chair Valérie Masson-Delmotte. “We now have a much clearer picture of the past, present and future climate, which is essential for understanding where we are headed, what can be done, and how we can prepare.”

With 1.5°C of global warming, Earth will see more heat waves and longer warm seasons. At 2°C, the report predicts that “heat extremes would more often reach critical tolerance thresholds for agriculture and health.…”

Highlights of the report

The report reveals that climate change involves more than just temperature changes. It encompasses “changes to wetness and dryness, to winds, snow and ice, coastal areas and oceans,” such as:

  • “Climate change is intensifying the water cycle. This brings more intense rainfall and associated flooding, as well as more intense drought in many regions.
  • Climate change is affecting rainfall patterns. In high latitudes, precipitation is likely to increase, while it is projected to decrease over large parts of the subtropics. Changes to monsoon precipitation are expected, which will vary by region.
  • Coastal areas will see continued sea level rise throughout the 21st century, contributing to more frequent and severe coastal flooding in low-lying areas and coastal erosion. Extreme sea level events that previously occurred once in 100 years could happen every year by the end of this century.
  • Further warming will amplify permafrost thawing, and the loss of seasonal snow cover, melting of glaciers and ice sheets, and loss of summer Arctic sea ice.
  • Changes to the ocean, including warming, more frequent marine heatwaves, ocean acidification, and reduced oxygen levels have been clearly linked to human influence. These changes affect both ocean ecosystems and the people that rely on them, and they will continue throughout at least the rest of this century.
  • For cities, some aspects of climate change may be amplified, including heat (since urban areas are usually warmer than their surroundings), flooding from heavy precipitation events and sea level rise in coastal cities.”

Creating climate change solutions

“The report also shows that human actions still have the potential to determine the future course of climate,” according to IPCC. “The evidence is clear that carbon dioxide (CO2) is the main driver of climate change, even as other greenhouse gases and air pollutants also affect the climate.”

“Stabilizing the climate will require strong, rapid, and sustained reductions in greenhouse gas emissions, and reaching net zero CO2 emissions. Limiting other greenhouse gases and air pollutants, especially methane, could have benefits both for health and the climate,” says IPCC WGI Co-Chair Panmao Zhai.

AR6 WGI Interactive Atlas

One new feature of this year’s IPCC AR6 WGI report is the addition of an Interactive Atlas, which has two components:

The Regional Information component “includes the ability to generate global maps and a number of regionally aggregated products (time series, scatter plots, tables, climate stripes, etc.) for observed and projected climate change for time periods, emissions scenarios or global warming levels of interest.”

The Regional Synthesis component “provides qualitative information about changes in climatic impact-drivers (CIDs) in several categories such as heat and cold, wet and dry, or coastal and oceanic. Users can select one or several impact-drivers and visualize the regional historical trends and projected changes over the sub-continental reference regions.”

This data provides policymakers, stakeholders, and the public with valuable data and tools.

What is industry’s role?

Back in November 2019, Forbes magazine published a series of four articles entitled “How to Reach U.S. Net Zero Emissions by 2050.” The topics of the individual articles were decarbonizing industry, decarbonizing electricity, decarbonizing buildings, and decarbonizing transportation.

“Energy Innovation previously modeled a scenario to achieve the U.S. Paris Agreement pledge using the peer-reviewed, free, and open-source Energy Policy Simulator (EPS); it now uses the EPS to explore an illustrative policy package to achieve net zero U.S. emissions,” according to Forbes. “By 2050, the net zero pathway abates more than 6 Gt (gigatons) of emissions a year and saves more than 120,000 American lives per year due to reduced particulate pollution.”


U.S. industry produces 35% of GHG emissions, “or 29% if all emissions from generating electricity are grouped into a separate ‘electricity’ sector,” Forbes says.

In 2018, the largest industry contributors were:

  • Natural gas and petroleum—40%
  • Chemicals and plastics—27%
  • Cement/concrete—4%
  • Coal mining—4%
  • Iron and steel—4%

Industry emissions abatement recommendations mentioned in the Forbes article include:

1.  Electrification of some processes that currently utilize fossil fuels and the production of hydrogen from zero-carbon electricity for use as a reactant and thermal fuel will result in 38% of the desired abatement.

2. Smart design to create more efficient, longer-lasting, and reusable building materials, along with vehicle sharing, accounts for 21% of the EPS abatement scenario.

3. Phasing out and replacing fluorinated gases (F-gases) with more environmentally friendly choices would add 14% to the abatement goals.

4. Capture and destroy methane gases (8%).

5. Carbon tax (6%).

6. Energy-efficiency standards for industry (3%).

7. Other policies and technologies such as improved worker training and policies to reduce demand, including “carbon-free electricity standard, an electric vehicle sales mandate, building electrification, and transitioning hydrogen production to electrolysis,” along with general reductions in fuel use and emissions, account for the rest of the EPS abatement scenario for industry, according to Forbes.


The most effective methods for decarbonizing the generation of electricity are clean energy standards (CESs) and renewable portfolio standards (RPSs). These actions, along with power sector policies to increase transmission infrastructure and expanded grid flexibility, will achieve the bulk of the abatements necessary to decarbonize electricity, according to the EPS simulator.


“In the net zero policy pathway, an ambitious sales mandate requiring all-electric new equipment and appliance standards by 2035 drives the overwhelming majority of emissions reductions in buildings,” Forbes notes.

Electrification instead of natural gas heating and green building codes will also significantly reduce GHG emissions from buildings in the future.


Transportation emissions account for 27% of 2018 U.S. GHG emissions, according to Forbes. Achieving net-zero emissions in the transportation sector by 2050 would require an immediate phaseout of the sales of new petroleum-burning vehicles.

“If a ban on new fossil fuel vehicle sales only comes into force in 2050, many polluting vehicles will still be on the roads in that year,” Forbes adds.  “Accordingly, the net zero pathway requires 100% of all newly-sold cars, SUVs, motorcycles, buses, and rail locomotives, as well as 50% of medium- and heavy-duty trucks, to be all-electric via electric vehicle policies by 2030.”

Creating transportation demand management (TDM) policies will achieve 13% of the abatement necessary for this sector. These policies will shift modes of travel to those with lower emissions, such as walking, biking, buses, rail lines, and ships.

Other policies important for abatement in this sector include hydrogen vehicle sales mandates and higher vehicle emissions standards.

About the IPCC

“The [IPCC] is the UN body for assessing the science related to climate change. It was established by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO) in 1988 to provide political leaders with periodic scientific assessments concerning climate change, its implications and risks, as well as to put forward adaptation and mitigation strategies,” according to the IPCC. “In the same year the UN General Assembly endorsed the action by the WMO and UNEP in jointly establishing the IPCC. It has 195 member states.”

The AR6 WGI has 284 authors from 66 countries, including 81 coordinating authors, 167 lead authors, and 86 review editors. Additionally, there were 517 more contributing authors, with more than 14,000 cited references and a total of 78,007 expert and government review comments.

See the IPCC’s AR6 WGI full report.