Paul C. Hutton
Published 3 years ago.
About a 4 minute read.
Image: Carlo Yuen/Pixabay
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The reduction in total carbon emissions due to COVID-19 just about equals the annual reduction we need to put in place over the next decade. That’s quite a challenge — and it will require us to examine every aspect of our organizations’ operations.
In our previous articles on carbon and the built environment, we covered these
Carbon reporting for real estate
Operating vs embodied carbon in the built
Carbon sequestration in the built
As individuals, governments, organizations and corporations begin to track the
amount of greenhous gas (GHG) emissions for which they are responsible, the
question frequently arises: “Now that I know our carbon footprint (annual CO2e
emissions) what should I do about it?”
At Cuningham Group, we
advise our clients to develop a carbon budget specific to their operations. The
carbon budget of any entity can be mapped against a number of different
scenarios for the global carbon budget. The result is a roadmap for
GHG-emissions reduction that can be followed and implemented by that entity.
Scientists are able to estimate the total amount of GHG emitted into the
atmosphere since the beginning of the Industrial Revolution. Through 2011, that
amount stood at 1,890 gigatons CO2e (CO2 equivalent — representing all
greenhouse gases and estimating their global warming impact as it they were
CO2). In 2019, human activities resulted in another 40 gigatons of CO2e. That
means that, in just one year, humans accounted for 2.1 percent of all the GHG
ever put into the atmosphere. It is clear to the scientific community that the
rate of 40 gigatons annually cannot continue without devastating consequences
for climate and life on our planet.
The Carbon Tracker Initiative defines a carbon
budget as “the cumulative amount of carbon dioxide (CO2) emissions permitted
over a period of time to keep within a certain temperature threshold.” Using
climate models, climate scientists can estimate the probability of not
overshooting the accepted 1.5° C target for maximum average global
temperature increase, with different amounts of total GHG remaining emissions.
Per the Architecture 2030
most current and commonly accepted values for this are:
600 gigatons = 33% chance (of staying at or below 1.5 degrees C)
500 gigatons = 50% chance
340 gigatons = 67% chance
The GHG amounts above are the totals from all human-related sources, until such
time as net emissions stop. Many governments have established timelines for the
complete elimination of net emissions by certain dates, such as 2030, 2040 or
2050. But do these timelines get us there fast enough?
A strictly linear reduction of GHG emissions from now until 2050 will result in
another 600 gigatons of CO2e being released into the atmosphere. That would be
an annual reduction of 3.3 percent, or 1.33 gigatons less per year. As seen
above, that results in only a 33 percent probability of limiting temperature
rise to 1.5° C. A more ambitious linear reduction that reaches net zero
in 2040 still results in total remaining emissions of 400 gigatons GHG. That
would be a yearly reduction of 5 percent, or 2.0 gigatons less per year. Even
this more ambitious plan doesn’t lead to a strong probability of avoiding 1.5° C increase. For this reason, the Architecture 2030 organization has
proposed a global carbon budget of 340 gigatons allocated per the chart below.
This plan proposes a more aggressive reduction between now and 2030, followed by
a slightly less rapid reduction leading to net zero emissions by 2040. This plan
leads to a 67 percent probability of limiting temperature increase to 1.5
degrees C average. The 65 percent reduction in emission over the next ten years
requires a commitment to 6.5 percent annual reduction.
Whatever your organizations carbon footprint and annual GHG emissions are now,
we recommend you consider a reduction plan similar to the chart above. That
requires a 6.5 percent annual reduction starting this year, to be followed by a
more gradual 3.5 percent reduction until 2040. If your organization can achieve
net zero GHG emissions sooner, all the better!
Our clients often ask: “Hasn’t COVID-19 already resulted in a drastic reduction
Do we need to do much more than that?” The answer is complex. Although most
organizations have substantially reduced GHG emissions due to transportation,
the building sector has generally not reduced emissions. Nearly empty
buildings are still running most of their heating, cooling and ventilating
systems. The World Meteorological Organization
the global reduction in GHG emissions for all of 2020 will be only 4.2 to 7.5
In other words, the reduction in total carbon emissions due to the COVID-19
pandemic just about equals the annual reduction we need to put in place over the
next decade. That’s quite a challenge — and it will require us to examine every
aspect of our organizations’ operations.
Note: This article concludes Cuningham Group’s four-part series on Carbon and
the Built Environment. Please contact us at
http://www.cuningham.com to find out more.
Published Dec 11, 2020 7am EST / 4am PST / 12pm GMT / 1pm CET
Paul Hutton, FAIA, NCARB is a LEED Fellow, and Chief Sustainability Officer at Cuningham Group Architecture, Inc.
This article, produced in cooperation with the Sustainable Brands editorial team, has been paid for by one of our sponsors.