You’ve probably gone to the grocery store recently, clutching your reuseable canvas bag and feeling good about protecting the environment. But did you know that a huge amount of water and fossil-fueled power went into producing that bag? Recent developments in Western states and local communities have brought focus to severe and persistent water shortages. Going forward, all our actions will require informed assessments through the lens of climate impacts.

A recent New York Times article presents a damning case on cotton tote bags’ impact on the environment: hard to believe when compared to single-use plastics. Why are these totes as bad as they are? Cotton is a thirsty crop, and much of it is grown in areas with insufficient precipitation. Moreover, the impact is worsened if the region where the cotton is grown and processed relies on fossil-fuels (e.g., coal) and the cotton is shipped long distances using fossil-fuel power. The top five cotton-producing countries — India, China, the U.S., Brazil, and Pakistan — collectively account for 75% of the world’s production.

While we often think of the carbon footprint as the ultimate measure of climate change, the cotton tote example brings up a related but different measure: virtual water. Virtual water is the total amount of water involved in providing a product or service:  the direct and indirect water used to grow, process, transport, package, and use the product. Virtual water can include natural rainwater (green water), groundwater and surface water (blue water), and the water required to clean wastewater (grey water) generated from production. Thus, products with high virtual water coming from water-scarce regions is equally as concerning regarding environmental impacts.

Cotton is a warm weather crop requiring about 130-160 days of warm days per crop. When grown in hot, sunny, dry, windy areas, additional water is necessary to compensate for these climatic factors. According to the National Cotton Council, growing cotton in arid areas requires 40 to 50 inches of water per year whereas in more humid and temperate climates it requires only 20 to 30 inches per year. This does not account for the water needed in the production of, for example, a cotton tote.

Texas is the leading state in the U.S. for cotton production. The primary growing area is in the South Plains area of West Texas has an annual average rainfall of 10 to 25 inches per year. Cotton is also grown in California’s Central Valley with annual average rainfall of 5 to 20 inches and in Pinal and Maricopa Counties in Arizona, with annual average rainfall of about 12 and 10 inches respectively. For reference, a desert is defined as an area receiving less than 10 inches of rainfall per year. To satisfy the requirements of a thirsty crop in a water scarce area, aquifers need to be tapped or, as in the case of California and Arizona, water is diverted from wetter areas and transported long distances for irrigation.

The U.S. is also a major exporter of cotton, primarily to China to produce textiles and apparel. Thus, it is possible that cotton grown in the U.S. is shipped to China to be turned into a cotton tote bag, which is then shipped back to the U.S.. This means that at each step in the life of a cotton tote, the amount of its virtual water increases and becomes part of global trade. In some cases, we export scarce water while simultaneously importing scarce water.

What can be done? As an individual, it is imperative to become a better-informed consumer and view purchases through a lens of climate impacts, which includes carbon footprints and virtual water. Yes, this is challenging because of the prevalence of irrelevant and misleading marketing claims (e.g., all natural, environmentally friendly) and the technical nature of some environmental impacts.

We can lobby our public officials to support and improve country of origin labeling, both for finished product and primary materials. We also need to develop succinct and informative product labeling to better inform consumers on water impacts, energy sources, and actual recyclability.

On a policy level, focusing all our attention on eliminating fossil fuels or increasing solar power while essential, is insufficient. We must reassess what we grow and where we grow it. Water and crops are heavily subsidized at the federal level, which undermines the appropriateness of crop locations: we should not be growing thirsty crops in deserts even if government subsidies allow it.

These are not easy tasks and there are no easy solutions. But we must respond to the climate emergency with the urgency that it warrants.

Travis Wagner, Ph.D. is professor in the Department of Environmental Science & Policy at the University of Southern Maine. His column reflects his views and expertise and does not speak on behalf of the university. He is a member of the Maine chapter of the national Scholars Strategy Network, which brings together scholars across the country to address public challenges and their policy implications. Members’ columns appear monthly.