How Can You Measure Your Environmental Impact?

Why Measure Environmental Impact

Before discussing how to measure environmental impact, it is essential to understand why. Why would we want to improve our environmental impact, and why do our homes matter?

To be blunt: the expanding population places an increased demand on the Earth's resources. Humanity is not living within the means of the Earth. The evidence is growing that humans are quickly using the available resources on Earth, and our demand for the natural ecosystem is consistently increasing. If everyone lived like the average American, we would require almost five Earths to sustain the resource consumption rates. Deforestation, ecosystem fragmentation, and waterway impairments are just a few examples of how human demand exceeds the availability of resources on Earth and negatively impacts the environment.

Sustainable, responsible development is one way we can mitigate these negative environmental impacts. Sustainable development was officially defined in 1987 as "development that meets the needs of the present without compromising the ability of future generations to meet their own needs." Ideally, sustainability serves both short-term and long-term goals while advancing environmental protection, social responsibility, and economic practices while promoting public environmental awareness and action.

How Do Buildings Impact the Environment

Sustainability applies to a variety of contexts, particularly within the building industry. Buildings account for 40 percent of carbon dioxide emissions and 70 percent of the electricity load in the United States, which is more than any other sector. Incredulously, three-quarters of total energy consumption in buildings is from residential uses.

The greenhouse gas emissions that homes produce are due to the energy used for heating and cooling, lighting, appliances, and other electric equipment. A majority of that energy comes from burning fossil fuels—primarily natural gas and coal. And if you include the greenhouse gas emissions from the manufacture and transportation of building materials, demolition, and other building activities, the environmental impacts from buildings are even higher.

In recent decades, the building trend has been to "go big," which has caused many detrimental environmental impacts, including loss of land, worse air pollution, higher energy consumption, and ecosystem fragmentation. This current building trend can have significant negative implications for the environment since building size is one of the most significant predictors of energy consumption for a building. In addition to building size, occupant behavior greatly influences energy consumption in a building. 

Need for Environmental Impact Metrics

Many different metrics have been developed to show our demand imposed on the Earth and the availability of resources to meet demand. Some metrics assess an individual's perception of their environmental impacts. The New Ecological Paradigm (NEP) scale, for example, measures the ecological concerns of individuals by providing fifteen statements and asking individuals to indicate the strength of their agreement/disagreement with each. Responses are then used to develop statistical measures of their environmental views. 

In contrast, other tools exist that assess the actual environmental impacts of individuals. Some studies have found that there is little correlation between these two types of metrics. Often, those who perceive themselves as having a low environmental impact do not have a reduced impact when a footprint calculator measures it. Why? The explanations range from a lack of awareness of the ecological effects of behaviors, social desirability, and limited memory and knowledge for those individuals who self-assess their environmental impacts. Therefore, to assess our environmental impact accurately, it is essential to use a footprint tool to identify actual behaviors rather than viewpoints.

The How: Footprints

The term "footprint" refers to a physical measurement of land and offers a broader environmental impact measure than other metrics measuring perceptions. The three most common footprint metrics include carbon footprint, water footprint, and ecological footprint. Generally speaking, an ecological footprint is considered the most comprehensive of the three. 

What is Carbon Footprint?

A carbon footprint refers to the amount of greenhouse gas emissions from an individual, process, or product. These are gases that trap heat in the atmosphere are the primary drivers of climate change. Carbon dioxide (CO2) comprises 82 percent of greenhouse gas emissions. But greenhouse gases also include methane, nitrous oxide, and fluorinated gases. So to simplify the equation, other greenhouse gases are converted into "carbon equivalents"—hence the term "carbon" footprint. It considers an individual's carbon emissions from home energy usage, food choices, transportation, and waste. Calculating a carbon footprint is the initial step towards calculating a "full carbon footprint," which is one component of an ecological footprint. Therefore, a carbon footprint is not as comprehensive as an ecological footprint since it is one component considered in calculating an overall ecological footprint.

What is Water Footprint?

Unlike a carbon footprint, a water footprint is considered a complementary sustainability metric to an ecological footprint. A water footprint measures the freshwater that an individual or population directly (and indirectly) uses based on their consumption habits. In conjunction with an ecological footprint, a water footprint helps us understand our total demand on the Earth and the pressures we exert on it.

What is Ecological Footprint?

An ecological footprint calculator is one of the most holistic metrics available, as it compares all human demands on nature, including food, housing, transportation, goods, and services. Other types of sustainability metrics exist, but the ecological footprint is the overarching metric to calculate the effect of human behaviors on our planet's ecosystem. It includes components of other popular sustainability metrics, enabling it to examine human demand on Earth broadly. For this reason, the ecological footprint calculator has emerged as the world's standard for the measurement of human demand on land and water areas.

Ecological footprints are a measure of the load imposed by a given population on nature. It represents the land area necessary to sustain current resource consumption and waste levels by a community, activity, or individual. The purpose of calculating an ecological footprint is to determine if consumption is environmentally responsible. It is also used to determine the amount of biologically productive area required by an individual, population, or activity to accommodate their consumption.

An ecological footprint calculator measures the amount of biologically productive land and sea area an individual, group of individuals, or activity needs to provide for their consumption. Many ecological calculators can be found online and thus are accessible by many. However, not all online calculators comply with rigorous standards set for ecological footprints. The following article in this series will explore a comparison between seven of the most popular ecological footprint calculators.

For reference, the ecological footprint of an average American is 8.4 global hectares (gha), the sixth-largest average in the world. To help reduce an individual's ecological footprint only to require one planet or less, we look toward the built environment. We homeowners can demand more efficient design, and we can change our behaviors. This underscores the importance of encouraging the residential sector to adopt innovative solutions and approaches to addressing housing size and occupant behavior.

Now, more than ever, we are in a position where it is imperative to reduce our environmental impacts and find innovative solutions within the residential sector. Rise readers have already taken steps to learn about sustainable homes. Stay tuned to learn more about how to measure your ecological footprint and how you might be able to use this information to make informed, effective changes in your journey.