Understanding Climate Neutrality

What's in a Name?

What are climate neutrality and carbon neutrality? While similar, climate neutrality and carbon neutrality are distinct concepts. According to the 2015 United Nations Climate Change Conference of the Parties (COP 21), these are defined as follows:

  • Climate neutrality is the same concept as carbon neutrality, but rather than solely focusing on carbon dioxide emissions, it extends to zero net human-caused greenhouse gas emissions (i.e., including emissions beyond just carbon dioxide such as methane, nitrous oxide, etc.). 
  • Carbon neutrality means zero net human-caused or influenced carbon dioxide emissions, or neutrality, achieved by a certain date. Thus, carbon neutrality is attained when every ton of human-caused carbon dioxide, or CO2, emitted is compensated for with an equivalent amount of carbon dioxide being removed (e.g., via carbon sequestration).

Greenhouse gases, like carbon dioxide, are gases that trap heat in the atmosphere, thus contributing to global warming and, as a result, climate change. Carbon dioxide, methane, nitrous oxide, and fluorinated gases such as hydrofluorocarbons and halons are the primary greenhouse gases of concern. According to the U.S. Environmental Protection Agency, the three critical measures that determine the harmful impacts of greenhouse gases are the length of time the gas remains in the atmosphere, the atmospheric concentration of the gas, and the amount of energy the gas can absorb (the more energy absorbed, the more detrimental warming effect the gas has).  

Scope Emissions

Greenhouse gas emissions are typically categorized into three scopes, depending on the source from which they are produced, described below.

Scope 1 GHG emissions

Direct emissions from sources that are owned or controlled by an organization. These include on-site fossil fuel combustion and fleet fuel consumption.

Scope 2 GHG emissions

Indirect emissions from sources that are not owned or controlled by an organization. These include emissions from the generation of electricity, heat, or steam purchased by an organization from a utility provider.

Scope 3 GHG emissions

Indirect emissions from sources not owned or directly controlled by an organization, but related to the organization’s activities. Scope three emissions include emissions from employee travel, including air travel and daily commuting, as well as waste disposal, wastewater treatment, the embodied GHG emissions of purchased products, and more.

Where Do We Stand?

The University of Arizona primarily monitors its climate footprint through an annual Greenhouse Gas Inventory. Planning, Development, & Facilities Management leads the development and publication of the institution’s full inventory of greenhouse gases, in close partnership with the Office of Sustainability and with contributions by Financial Services, Parking & Transportation Services, and other departments across campus. These departments participate in a collaborative effort to aggregate and analyze all of the necessary data for the Greenhouse Gas Inventory, which is published annually. Reports for FY2019, FY2020, and FY2021 are available below. Each report includes historical emissions inventories dating back to FY2015.  

University of Arizona FY2019 GHG Inventory
University of Arizona FY2020 GHG Inventory
University of Arizona FY2021 GHG Inventory
University of Arizona FY2022 GHG Inventory


Down to Zero

In 2018, under the University Strategic Plan, the University moved up its climate neutrality goal date from 2050 to 2040, understanding the need to lead in the promotion of a climate neutral economy. The University also set a goal of reducing scope two emissions on the Tucson campus by 100% by 2025, a goal that was achieved in July 2021 through our large-scale renewable energy agreement with Tucson Electric Power.

The History of Our Commitment to Climate Neutrality 

The University has a long history of engagement in sustainability initiatives. We first demonstrated its commitment to building a more sustainable future by becoming one of the charter signatories of the American College and University Presidents Climate Commitment (ACUPCC) in 2007. In 2015, Second Nature launched a new set of Presidents’ Climate Leadership Commitments for higher education institutions, offering the Carbon Commitment (formerly the ACUPCC), the Resilience Commitment, and the Climate Commitment, a combination of the former two commitments. Maintaining and expanding upon our original commitment, the University of Arizona became one of 93 charter signatories of those new commitments by then signing Second Nature’s Climate Commitment, pledging that the University would not only reduce its greenhouse gas emissions to zero by 2050, but also would integrate climate resiliency in partnership with the Tucson community, positioning the University to be a profound and dynamic force in southern Arizona with relation to climate change education, research, and preparedness. Under the 2018 Strategic Plan, the University of Arizona moved its climate neutrality goal date up from 2050 to 2040.