Tackling Climate IN Change Decatur This Environmental Sustainability Report details the new reality we’re in, highlights action the Decatur community is already taking, and offers ways you can get involved. It’s here. Changing Climate change is here. The scientific community agrees that growing seasons in human activity, primarily the burning of fossil fuels, is altering your garden. Hotter our atmosphere and climate at an unprecedented rate. The news of climate change focuses on western wildfires and summers. Prolonged melting ice caps. Still, impacts are being felt – and will continue droughts. Higher to be felt – here in Decatur. electricity bills. Human activity drives the changes in our climate. We can also Aspects of life in slow, stop and potentially reverse the problems we’re creating. Decatur are already Along the way, we can build healthier, more equitable, and under pressure. more resilient communities. Climate action will help us better handle future pandemics and economic downturns like the ones our nation currently faces. CITY OF DECATUR ENVIRONMENTAL SUSTAINABILITY REPORT 2020 HOW’S THE LIFE IN THE CLIMATE OUT GREENHOUSE THERE? SLIGHT TEMPERATURE CHANGES MAKE BIG IMPACTS ON OUR CIVILIZATION KNOW THE DISTINCTION Life on Earth is made possible by the greenhouse effect. Like BETWEEN WEATHER AND a blanket trapping your body heat to keep you warm, the CLIMATE greenhouse gases – carbon dioxide, methane, and water vapor Weather is the way the atmosphere – retain solar radiation reflected by the Earth and warm the behaves over short periods of time. globe. Without this retained solar energy, it’s likely there would Recently (as of April 24) Decatur’s weather be no life on this planet. Human activity, however, has increased has been rather windy. Two strong storm the atmospheric concentration of these greenhouse gases to a events have passed through the area. point where we are changing the Earth’s climate on a massive High daily temperatures have ranged from scale. about 56°F to 78°F. Our climate, though, Carbon dioxide is emitted primarily through the burning of is the accumulation of all those weather fossil fuels in transportation and electricity generation. CO2 has events, daily temperatures, precipitation reached an atmospheric concentration not seen for hundreds of totals and more, over long periods of time thousands of years. At 415 ppm (parts per million), atmospheric (typically more than 30 years). CO2 is significantly over the 350 ppm threshold that most When we talk about climate, we’re talking scientists agree to be the limit for “normal” climate functioning. about our average weather. Understanding These additions of carbon dioxide, methane (which is released this distinction is key to understanding largely by agriculture), and the other greenhouse gases have just how our climate. It helps us anticipate resulted in an estimated warming of 1°C from preindustrial (pre- average weather patterns next year and 30 1800s) levels. While this may not seem like much, even slight years from now. changes in average temperatures over long periods of time can have large impacts on human society and our environment. THE GREENHOUSE EFFECT Normal CO2 Rampant CO2 MORE HEAT ESCAPES INTO LESS HEAT SPACE ESCAPES INTO SPACE MORE HEAT LESS HEAT TRAPPED IN TRAPPED IN ATMOSPHERE ATMOSPHERE SOLAR SOLAR RADIATION RE-RADIATED RE-RADIATED RADIATION HEAT HEAT 2 | TACKLING CLIMATE CHANGE IN DECATUR | decaturga.com/bc-esb THROW SOME SHADE – IT’S GETTING HOT IN HERE CLIMATE CHANGE of stepping outside shoeless onto the AND THE URBAN HEAT pavement during the summer. Dark surfaces like asphalt absorb the solar As Decatur warms ISLAND EFFECT energy released by the sun and can from both global Decatur is going to get warmer. By reach temperatures as much as 50 how much depends on several things, degrees Fahrenheit higher than that and the local climate including what we do here at home. of the surrounding air. At the same change created by Over the past 30 years, Decatur has time dark surfaces are being added, averaged around 20 days annually vegetation is being removed and the how we develop, the with temperatures above 95 degrees ground is being sealed by impervious health impacts Fahrenheit. Projections show that surface, reducing the cooling effects will multiply. number increasing to around 45 days of evapotranspiration. per year by midcentury (2018 National This phenomenon is called the See the next Climate Assessment). Extreme Urban Heat Island Effect. Experts pages for steps heat, the leading cause of weather- like Brian Stone of the Georgia Tech we can take related death in the United States, is Climate Institute refer to it as local something that has an outsized effect climate change. Cities, which are to reduce our heat on the most vulnerable among us, accumulations of pavement and island temperature, from the very young and elderly to buildings, absorb solar energy during those without adequate housing and the day and release it over the late cool our city, and air conditioning. afternoon and early evening. During provide shade. Research shows that developed urban those times, cities can be up to 10 areas can warm at rates two to three degrees warmer than surrounding times the global average. Why? Think rural areas. ATMOSPHERIC CARBON DIOXIDE (CO2) 460 440 Normal CO2 Rampant CO2 420 NOW 400 MORE HEAT ESCAPES INTO 380 LESS HEAT 360 SPACE ESCAPES INTO SPACE 340 1950 MORE HEAT 320 For millennia, atmospheric carbon dioxide had never been above this line LESS HEAT TRAPPED IN 300 LEVEL TRAPPED IN ATMOSPHERE 280 ATMOSPHERE 260 LEVEL (parts per million) LEVEL 240 2 SOLAR SOLAR 220 CO RADIATION RE-RADIATED RE-RADIATED RADIATION 200 HEAT HEAT 180 160 800,000 700,000 600,000 500,000 400,000 300,000 200,000 100,000 0 YEARS BEFORE TODAY (0 = 1950) NASA, The relentless rise of carbon dioxide” Sustainability Report 2020 | 3 TREES AND STREAMS OFFSET SWELTERING SUMMER TEMPS Eighty percent of all Americans live in channelization, and storage basins, Last year was the hottest on record urban areas. As density increases, so others – including Decatur – are for Georgia and this year is already do impervious surfaces – more streets, creating green drainage systems to on course to bring even greater parking lots, rooftops and driveways manage stormwater more efficiently. sweltering temperatures.. Studies – causing drainage problems to This prevents flooding, improves water suggest that a well-vegetated stream intensify. While many cities treat runoff quality, and reduces the heat island buffer can reduce temperatures up to with conventional piping, stream effect on city temperatures. 10 degrees during hot summer days. The shade of a single tree can provide welcome relief from the hot summer sun. But when that single tree is part of a small forest, it creates a profound cooling effect.” — Proceedings of the National Academy of Sciences, March 25, 2019 CREATE A THERMAL to its floodplain slows down water microclimate. They also help our city flow to reduce erosion; allows water maintain its 40 percent tree canopy REFUGE IN YOUR to percolate into the ground; and target. OWN BACKYARD provides habitats for wildlife, including Additional measures a homeowner can birds, bees, amphibians, and fish. take for a “cooler” summer include With more than 80 percent of trees If every Decatur landowner whose installing rain gardens and/or green and streams in private ownership in property includes a natural stream roofs, and planting more shrubs, trees, Decatur, many residents can create plants and maintains trees along the and under-story vegetation. Visit “thermal refuges” in their own stream corridor, they help create www.sustainableprinceton.org/yard for backyards. A natural stream connected a linear urban forest with a cooler more information. 4 | TACKLING CLIMATE CHANGE IN DECATUR | decaturga.com/bc-esb Think Outside that Little Box day. Electricity usage matters because TACKLE CLIMATE electricity from a mix of resources, power generation accounts for roughly including company-owned power a third of our economy’s total green- CHANGE AT THE plants, power purchased from other house gas emissions each year (Source: producers, and demand-side manage- ELECTRIC METER EIA). Below, see several ways Decatur ment programs. As the figure on the As Decatur residents look for ways to residents can tackle climate change at next page shows, natural gas and coal reduce our individual carbon footprints, the electric meter. one place to begin is at the little box account for about 70 percent of the on the side of our homes. It measures How is our electricity produced? Here energy resources we use. Carbon-free how much electricity we consume each in Decatur, Georgia Power supplies renewable energy such as solar power more ROOFTOP SOLAR PANELS RENEWABLE ENERGY Imagine producing your own carbon-free elec- CERTIFICATES (RECS) tricity, while saving money on your monthly A REC supports investment in renewable energy projects power bill. You can, thanks to important policy by selling credits based on units of electricity produced changes at the state level that have spurred by wind farms, solar installations, or other clean energy the rapid growth of Georgia’s solar industry projects. RECs are bought and sold separate from the and lowered panel and installation costs. electricity itself, so you can claim credit for this green Georgia Power also has programs that com- energy even if you buy electricity from local utilities. pensate homeowners for excess solar power Large companies rely on RECs as a practical and cost- sent to the electric grid. Homeowners can effective strategy to meet their clean energy goals. purchase rooftop solar systems as a group Decatur residents can purchase RECs through the through Solarize Decatur-DeKalb 2.0, reduc- Georgia Power Simple Solar program that matches up to ing installation costs and 100 percent of your monthly electricity usage with REC speeding up the permitting purchases from solar projects around the state.