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How Much the World Warms Depends on Us

One of the questions I am most frequently asked about climate change is “what can I do”. Indeed, the problem is so big, and the scale of the global response required, so large, as to reduce many of us to believe there is little if anything we can do about it. The reality is that we can do a lot — our climate future is ours to determine.

In remarkably stark terms, the scientific community is telling us the time for addressing climate change is running out. Any further delay “will miss a brief rapidly closing window to secure a livable future.” Although scientific uncertainties remain, a striking conclusion mostly missing from the press coverage and messaging is that how bad it gets depends a lot — often primarily — on human decisions. The single greatest source of uncertainty about future climate is human behavior. Household decisions about what we eat, how we power our homes, and what transportation choices we make account for over 70 percent of global greenhouse gas emissions. How we live our lives can either make things a lot better or a lot worse. The more we understand this, the more likely we are to take climate actions.

The following describe a few of the individual and household decisions that will have the greatest impact on our climate future.

Adjusting thermostats and improving the efficiency of appliances

Energy use in buildings accounts for almost a third of U.S. GHG emissions. Reducing your home energy use saves money and reduces your contribution to climate change. Lower the temperature 7°-10°F while away at work or play (6 to 8 hours) and you can save about 10 percent on your heating and cooling bill and reduce your GHG emissions. You can save money and energy and reduce GHG emissions in your home by using compact fluorescent (CFL) and light-emitting diode (LED) bulbs, and by insulating your hot water heater.

Diet

Meat consumption is responsible for at least 14 percent of global greenhouse gas emissions, by some estimates more than twice that. Even the lower figure is equivalent to the total contribution of transportation. Cows burp and fart methane, a greenhouse gas more than 80 times as powerful as CO2 when compared over 20 years. Additional GHGs result from clearing forests for grazing land, growing corn and other plants for feed, and transport to feedlots and markets. Eating less beef has already been a trend in the U.S. driven by health considerations, with multiple plant-based alternatives making it even easier to eat healthily — a behavior change that also saves money.

Food Waste

Food waste along the entire supply chain — particularly in households but also at the farm, in grocery stores, and restaurants — accounts for 8 percent of warming. This source can be reduced initially through better meal planning but also by composting, which eliminates the production of methane from organic materials in landfills and results in an organic material beneficial for gardening. While composting can be done at the household level, a growing number of cities offer the service in addition to trash pickup.

Choice of transportation

Energy for transportation is responsible for about 28 percent of U.S. GHG emissions. There are three ways of reducing this source of emissions: increasing the efficiency of vehicles, changing how we travel, and using lower carbon fuels. As individuals we can choose a more fuel-efficient vehicle, travel by public transport, bicycle, or walking, and switch from a gasoline-powered vehicle to an electric one (ideally with access to electricity from a utility not overly dependent on fossil fuels). The International Energy Agency estimates that replacing flights under one hour with low-carbon alternatives, walking or cycling instead of driving by car for trips under 2 miles, and reducing road traffic speeds by 5 mph would reduce transport sector CO2 emissions by more than 20 percent.

Choice of apparel

The apparel industry is responsible for between 2 and 8 percent of global emissions. There are several ways consumers can reduce the emissions from their clothing choices including buying from environmentally-oriented companies with a commitment to climate-friendly materials and production, buying second hand, and keeping what’s in your closet longer and finding ways to update it. One need not go quite as far as Greta Thunberg who proudly noted last August she last bought a new item of clothing three years ago and “it was second hand.”

Choosing a fuel source for electricity in your home

Clean energy companies are emerging that will install and finance solar panels to eliminate fossil fuel use in your home. While not practical for everyone, in a growing number of states, consumers can now reduce their GHG emissions through the choice of their electricity supplier. In at least nine states, deregulation of electricity markets gives consumers some flexibility to choose their supplier without changing the distribution company that powers their home. The choices include companies that obtain power from wind or solar generation. For example, one company aggregates the power demand from enough consumers to cover the cost of a solar farm, avoiding the need for rooftop panels and without any change in the delivery and billing of power from the local utility.

“Voting with your dollars”

Many of the largest commercial banks continue to invest large sums in fossil fuel production and use — trillions of dollars in recent years. Pension funds are also increasingly disclosing their exposure to climate risk. Consumers can influence these large institutions if enough act together. A growing number of new smaller banks have emerged emphasizing their environmental philosophy and alternatives like credit unions also are not investors in fossil fuel production. Again, the impact of individual action may be minimal, but collective switching could make a real difference.

These are just a few actions consumers — especially those with higher incomes — can take. There are many more ways individuals can directly and indirectly take action to reduce greenhouse gas emissions and global warming such as flying less (and buying carbon offsets when you do), using less plastic (expected to exceed coal as a source of CO2 by 2030), replacing gas stoves with induction burners, bundling errands and on-line purchases to reduce trips, and favoring grocery stores and other vendors with a commitment to sustainability practices. If enough of us do something the impact will be considerable without much if any sacrifice.

In my next blog I will review how our vulnerability to climate change also depends a great deal on actions we take as individuals, e.g., choosing whether to live in an area at risk of flooding from sea level rise and more intense rainfall.

Alan Miller is a former climate change officer in the International Finance Corporation (2003–13) and climate change team leader, Global Environment Facility (1997–2003)