cities

Pandemic Lockdowns And Carbon Emissions | Earth Wise

November 25, 2020 By EarthWise Leave a Comment

The early months of the COVID-19 pandemic saw many human activities reduced to a fraction of what they were previously. Notably, air pollution in major cities was dramatically lower than it had been in decades. Now, a new study has looked at the effect of the pandemic shutdowns on carbon dioxide emissions.

An international team of climate scientists has published an assessment of carbon dioxide emissions by industry, transportation, and other sectors from January through June. According to their measurements, this year’s pandemic lockdowns resulted in a 9% decline in emissions from 2019 levels.

An earlier study reported a 17% drop in CO2 emissions, but the new study was more comprehensive and detailed.

The new data includes estimates of day-by-day, sector-specific and country-level differences in CO2 emissions derived from frequently updated data sources, some of which are nearly in real-time. It tracks the effects of COVID-19-related disruptions of human activities in China starting in February and in the United States and Europe in March through May.

The data revealed the resumption of emissions in many regions, such as in China, where they are now back to pre-pandemic levels. Emissions in the Americas and Europe have been slower to recover, especially in the US, where COVID-19 hotspots are continuing to emerge.

The reduction in carbon emissions has been due mostly to transportation with fewer people driving to work and traveling by air. Even by June, when lockdowns were easing, global emissions were still significantly reduced. In any case, a pandemic is a highly undesirable and unwelcome way to reduce carbon emissions, but the data from this year does show that it is effective.

**********

Web Links

Pandemic lockdowns caused steep and lasting carbon dioxide decline

Photo, posted August 7, 2020, courtesy of Michael Mueller via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Better Paint For Cooler Buildings | Earth Wise

August 20, 2020 By EarthWise 2 Comments

A research team led by scientists at UCLA have developed a super-white paint that reflects as much as 98% of incoming heat from the sun. Such paint, if used on rooftops and other parts of buildings, could have a major impact on reducing the costs of keeping buildings cool.

Passive daytime radiative cooling is a well-known method to keep buildings cooler. By having building surfaces reflect sunlight and radiate heat into space, building temperatures can be significantly lowered. This in turn cuts down on air conditioner use and associated carbon emissions.

A roof painted white will result in lower indoor temperatures than a darker roof. But a white roof will do even more: it can reject heat at infrared wavelengths that are invisible to our eyes. This results in even more radiative cooling.

The best performing white paints currently available reflect about 85% of incoming solar radiation. The rest is absorbed by materials in the paint. The new research has identified simple modifications in paint ingredients that lead to a major increase in reflectivity.

Current reflective white paints use titanium dioxide, which absorbs UV radiation and therefore heats up under sunlight. The researchers studied replacing it with other substances such as barite – an artist’s pigment – or with powdered Teflon, both of which allow the paint to reflect more of the sun’s radiation.

Many cities are encouraging the use of cool-roof technologies on new buildings. Using the most reflective coatings possible on rooftops, if applied on a sufficiently large scale, could have a real impact on climate change as well as saving significant amounts of energy used for running air conditioners in buildings.

**********

Web Links

UCLA-led Team Develops Ways to Keep Buildings Cool with Improved Super White Paints

Photo, posted August 15, 2012, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Benefits Of A Zero-Emissions Boston | Earth Wise

May 25, 2020 By EarthWise Leave a Comment

Many countries, states, and cities around the world have set goals to become carbon neutral, typically by the year 2050. These goals are based on the desire to mitigate the effects of climate change that are steadily increasing as a result of the buildup of carbon dioxide in the atmosphere. But reducing emissions is not just a way to combat climate change, it can also be a major contributor to improved public health.

The City of Boston has set a goal to become carbon neutral by 2050. A new study by the School of Public Health at Boston University published in the journal Environmental Research Letters looked at the consequences of eliminating fossil fuel emissions in the greater Boston area.

According to their modeling, eliminating emissions would save 288 lives a year by reducing fatal and non-fatal cardiovascular and respiratory illnesses. The resulting decrease in medical costs and lost and reduced work could save $1.7 billion a year in Suffolk County and $2.4 billion a year for the entire 75-square-mile zone modeled in the study.

The study looked at the amounts of two air pollutants known to harm human health: PM2.5 (particulates with a diameter of less than 2.5 microns) and ozone. They compared the current levels of these pollutants to what would be present when contributions from motor vehicles, generators, rail, industry, oil- and gas-burning, shipping and boating, and residential wood fires were eliminated.

The study focused on the City of Boston’s climate action plan, but actions taken by Boston will not take place in a vacuum. Many cities across the region are taking similar actions. The overall results will come from the collective actions across New England.

**********

Web Links

A Zero-Emissions Boston Could Save 288 Lives and $2.4 Billion Annually

Photo, posted August 31, 2019, courtesy of Eric Kilby via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Immersion In Nature Is Good for You | Earth Wise

February 20, 2020 By EarthWise Leave a Comment

There is a growing body of research that shows that getting outdoors in nature can be good for people’s health and well-being. There are so many studies supporting this idea that policymakers, employers, and healthcare providers are increasingly considering this need for nature in how they plan and operate.

A new study of 20,000 people by researchers at the University of Exeter in the UK actually looked at how much exposure to nature was enough to make people say they feel healthy and have a sense of well-being. The answer turned out to be 2 hours a week. And the correlation was strong. People who didn’t meet that threshold did not report the benefits.

Studies have shown that time in nature – as long as people feel safe where they are – is an antidote for stress. It can lower blood pressure and stress hormone levels, reduce nervous system arousal, enhance immune system function, increase self-esteem, reduce anxiety, and improve mood. Most of these studies are correlational rather than causal, but the results tend to be robust.

Given all this, cities are adding or enhancing parks, and schools and other institutions are being designed with large windows and access to trees and green space. The Scandinavian tradition of “forest schools” – where learning takes place in natural settings outdoors -.is finding a home in the US. Japanese researchers study the effects of “forest bathing”, a poetic term for walking in the woods.

With two-thirds of humanity projected to be living in cities by 2050, we are awakening to the idea that we need to be able to spend time in nature for our own wellbeing, even if it’s just a walk in a park.

**********

Web Links

Ecopsychology: How Immersion in Nature Benefits Your Health

Photo, posted November 6, 2011, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rising Seas Will Erase Cities

December 18, 2019 By EarthWise Leave a Comment

According to new research, climate-driven sea level rise could affect three times more people by 2050 than previously thought. This sobering assessment means some of the world’s great coastal cities, including Bangkok, Shanghai, Mumbai, Basra, Alexandria, and Ho Chi Minh City, could be in big trouble.

Scientists have always relied on land elevation data to determine the effects of sea level rise over large areas. But standard elevation measurements using satellites struggle to differentiate the true ground level from the tops of trees or buildings. The authors of the paper developed a more accurate way to calculate land elevation by using artificial intelligence to determine the error rate and to correct for it. The new findings revealed that 150 million people – three times more than previously thought – are now living on land that is projected to be below the high-tide line by the middle of this century.

Eight Asian nations – China, Bangladesh, India, Vietnam, Indonesia, Thailand, the Philippines, and Japan – account for about 70% of the people living on at-risk land.

More than 20 million people in Vietnam, including much of Ho Chi Minh City, live on land that will be inundated by 2050. In Thailand, more than 10% of its citizens, including much of Bangkok, currently live on land imperiled by projected sea level rise.

This new research was produced by Climate Central, a New Jersey-based science organization, and was recently published in the journal Nature Communications.

Sea level rise is clearly not just an environmental problem. It’s a humanitarian crisis.

**********

Web Links

New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding

Rising Seas Will Erase More Cities by 2050, New Research Shows

Photo, posted December 18, 2009, courtesy of Misko via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Benefits Of Zero-Carbon Cities

November 8, 2019 By EarthWise Leave a Comment

A new report issued by a coalition of 50 leading international institutions shows that low carbon initiatives in cities could reduce urban emissions by nearly 90% and support 87 million jobs worldwide by 2030. The report finds that implementing low carbon measures in cities would be worth almost $24 trillion by 2050.

Cities are home to more than half the world’s population but produce 80% of gross domestic product and 75% of carbon emissions. The research highlights the significant benefits carbon reduction can bring to cities in areas such as public health, job creation, and poverty alleviation.

The report shows that it is possible to cut 90% of emissions from cities using currently available technologies and practices including carbon savings from buildings, transportation, materials efficiency, and waste reduction. Doing so would require an investment of nearly $2 trillion per year but would generate annual returns of nearly $3 trillion in 2030 and $7 trillion in 2050 based on cost savings alone. Many low carbon measures would pay for themselves in less than five years, including more efficient lighting, electric vehicles, improved freight logistics, and solid waste management.

In addition to economic benefits, compact, connected and clean cities could provide a higher standard of living and greater opportunity for all. These measures would also reduce air pollution, cut chronic traffic congestion, and improve worker productivity.

The report offers case studies from around the world where national and local governments have worked together to rapidly and profoundly transform their cities for the better within 20 or 30 years.

**********

Web Links

The benefits of investing in zero-carbon cities

Photo, posted September 8, 2018, courtesy of Steffen Flor via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Electric Buses In Latin America

October 31, 2019 By EarthWise Leave a Comment

Latin America has become increasingly urbanized. In fact, about 80% of the region’s population lives in cities today and by 2050, that figure could climb to 90%. Transportation is the largest and fastest-growing source of energy-related emissions in Latin America and accounts for about a third of all of the region’s carbon dioxide emissions.

Private vehicle ownership is rising in Latin America but at the same time, the region’s rapidly growing cities have increased demand for buses, taxis, and motorcycles. Currently, an estimated 64,000 people die prematurely every year in Latin America and the Caribbean as a result of air pollution, which is mostly caused by transportation emissions.

Given this situation, major cities across Latin America – from Colombia to Argentina – are starting to adopt electric bus fleets. Latin America actually has the highest use of buses per person globally. So, the transition to electric buses is an important step toward meeting climate targets, cutting fuel costs, and improving air quality.

Medellin, Colombia – whose metropolitan area has 3.7 million people – has started to add electric buses to its fleet, the rest of which runs on natural gas. When new units arrive from China later this year, Medellin will have the second largest electric bus fleet in Latin America, after Santiago, Chile.

Worldwide, 425,000 electric buses are in operation, 99% in China. Europe has a couple of thousand while the United States has only 300. But going forward, and especially in Latin America, electric buses are the wave of the future. Estimates are that there will be 1.3 million on the roads by 2040.

**********

Web Links

An Increasingly Urbanized Latin America Turns to Electric Buses

Photo, posted April 22, 2018, courtesy of Hans Johnson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Which Cities To Save From The Changing Climate

October 28, 2019 By EarthWise Leave a Comment

After several years of brutal flooding and hurricanes in the U.S., a distressing debate is emerging: if there is not enough money available to protect every coastal community from the effects of global warming, how do we decide which ones to save first.

Recent research looked at the costs involved in providing basic storm-surge protection in the form of sea walls for all coastal cities with more than 25,000 residents. That number was $42 billion. Expanding the list to include communities smaller than 25,000 people would increase that cost to more than $400 billion. Realistically, that is just not going to happen.

This particular study only looked at sea walls and no other methods for minimizing flood risk, such as moving homes and businesses away from the most flood-prone areas. It also didn’t look at additional and costlier actions that will be required even with sea walls, such as revamping sewers, storm water, and drinking water infrastructure.

The facts are that many cities, especially small ones, will not be able to meet the costs facing them. Those that can’t will depend on federal funding. But even optimistically large proposals for federal infrastructure spending are likely to fall far short of the vast need. Ultimately, the money will end up being spent where it can do the most good – even if it means that some places are left out.

But what criteria will be used to direct the money? Economic value? Historic significance? Population? Political influence?

This is a looming and massive issue whose chief obstacle may be that many officials refuse to acknowledge that it is happening. This is the next wave of climate denial – denying the costs that we are all facing.

**********

Web Links

With More Storms and Rising Seas, Which U.S. Cities Should Be Saved First?

Photo, posted October 31, 2018, courtesy of Patrick Kinney via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Europe Is Warming Faster Than Predicted

October 9, 2019 By EarthWise Leave a Comment

A new study has found that Europe is warming faster than even climate models projected. The number of summer days with extreme heat in Europe has tripled since the 1950s, while the number of days with extreme cold has decreased by factors of two or three depending on the region.

According to climate scientists at the Swiss Federal Institute of Technology in Zurich, the climate trends are much larger than what would come from natural variability and are a clear signal of climate change. Extremely hot days in Europe have become hotter by an average of more than 4 degrees Fahrenheit while extremely cold days have warmed by more than 5 degrees. The research examined data from weather stations across Europe from 1950 to 2018. Over 90% of the stations recorded increasing temperatures over time, a percentage much too high to be purely from natural climate variability. The results also showed that the region was warming even faster than climate models projected.

The research results come after an extremely hot summer in Europe. Southern France hit 114.8 degrees, a new record, in June. Germany, the Netherlands, and Belgium all recorded all-time national temperature highs. The National Oceanic and Atmospheric Administration recently announced that July was the hottest month ever recorded.

European summers and winters will only grow hotter in the coming years as climate change accelerates. The rapidly increasing temperatures will impact cities and people that are unprepared for them and pose real risks for residents in the coming decades. Extreme heat is dangerous because it stresses the human body, potentially leading to heat exhaustion or heat stroke.

**********

Web Links

Europe warming faster than expected due to climate change

Photo, posted July 30, 2011, courtesy of Marcel de Jong via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Cost Of Rising Seas

October 1, 2019 By EarthWise Leave a Comment

Coastal cities in the United States are grappling with the need for extensive infrastructure projects to protect against rising seas and worsening storms. The cost of these projects will be enormous, and it is unclear how to pay to them.

Boston has many neighborhoods in low-lying areas, and it is estimated that $2.4 billion will be needed to protect the city from flooding. The city abandoned plans to build a harbor barrier that would have cost $6 to $12 billion because it was economically unfeasible.

Charleston, South Caroline needs $2 billion to reduce flooding that occurs regularly during high tides. The Houston, Texas area needs $30 billion to provide protection against a 100-year flood. Hurricane Harvey caused $125 billion in damages in Texas in 2017. New York City is considering a $10 billion storm surge barrier and floodgates to shield parts of the city from rising waters.

Florida faces the greatest exposure to flooding with an estimated $76 billion in costs to address some of its problems.

At the federal level, multiple agencies represent potential funding sources, but none offer the kind of money required to address the need. This places a heavy burden on state and local governments. Various states have passed legislation related to shoreline resiliency and flood abatement, but relatively little funding has been approved. Some bond measures have passed, but the totals are small compared with what is needed.

Educating people about the costs of not doing anything or not doing enough soon enough is essential. As Hurricane Katrina demonstrated, not spending a large amount of money on resilience can result in having to spend a colossal amount of money on recovery.

**********

Web Links

Who Will Pay for the Huge Costs of Holding Back Rising Seas?

Photo, posted December 26, 2013, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fighting Climate Change With Trees

August 20, 2019 By EarthWise Leave a Comment

We cut down forests all around the world for a myriad of reasons, including livestock grazing, agricultural production, timber, and urban development. But what if we stopped cutting down forests for these things and additionally grew new forests on vacant lots and any other available parcels of land on earth? What impact could this have on our survival?

For the first time, scientists have quantified what impact this plan could have. According to a new study by researchers at ETH Zurich – a university that specializes in science, technology, and engineering – the planet could support nearly 2.5 billion additional acres of forest without shrinking current cities and farms. When all those acres of forest mature, the trees could store an extra 200 gigatons of carbon. This reforestation could stave off the most devastating impacts of global climate change.

Russia could restore the most acres of forest – 373 million acres to be precise – followed by the United States with 255 million acres and Canada with 193 million acres. Australia, Brazil, and China also have large areas well-suited for forest restoration.

The average global temperature has risen by 1.8 degrees Fahrenheit since the start of the industrial age with its surge in greenhouse gas emissions. Temperatures are projected to rise even more in the coming years as the planet continues to warm.

Trees absorb CO2 from the atmosphere and store it in their roots and branches. The absorbed carbon becomes part of the soil when trees die and decompose, and it can linger there for millennia depending on things like temperature and soil management. Trees are critical in the fight against climate change.

**********

Web Links

How trees could save the climate

Photo, posted June 18, 2011, courtesy of K.W. Barrett via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Dangerous Cities For Migrating Birds

May 14, 2019 By EarthWise Leave a Comment

Billions of birds migrate north in the spring and south in the fall. The majority of them fly at night. But as they pass over large cities, the birds can become disoriented by bright artificial light – so-called light pollution, causing them to crash into buildings or windows.

Researchers estimate that 600 million birds die from building collisions in the United States every year. Now, a new paper from researchers at Cornell University reveals which metropolitan areas are most dangerous for birds and why.

The researchers ranked cities where, as a result of geography and exposure to light pollution, birds are at the greatest risk of becoming attracted to and disoriented by lights and crashing into buildings. They combined light pollution levels with bird density data in order to make their calculations. Their paper was recently published in the journal Frontiers in Ecology and the Environment.

Chicago, Houston, and Dallas finished as the three most dangerous cities for migrating birds. While migration routes vary depending on the season, these three cities still topped all others during both the spring and fall migrations due to their size and geographic positioning in the heart of North America’s most trafficked aerial corridors.

Audubon’s Lights Out program is one of several national efforts encouraging cities to reduce light pollution, particularly on heavy migration nights, in order to reduce bird mortality.

But homeowners need to do their part as well since an estimated quarter-million birds die from collisions with residential houses every year. The suggestion to cities and homeowners alike is the same: If you don’t need the lights, turn them off.

**********

Web Links

Chicago tops list of most dangerous cities for migrating birds

Photo, posted May 18, 2017, courtesy of Pedro Szekely via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

China And Plastic Waste

April 26, 2019 By EarthWise Leave a Comment

In January 2018, China enacted its “National Sword” policy which banned the import of most plastics and other materials headed for that country’s recycling processors. Those processors had handled nearly half of the world’s recyclable waste for the past quarter century. China took this step because the deluge of soiled and contaminated materials was overwhelming its processing facilities and creating yet another environmental problem for the country, this time not even of its own making.

Prior to China’s ban, 95% of the plastics collected for recycling in the European Union and 70% in the U.S. were sold and shipped to Chinese processors. A combination of favorable rates for shipping in cargo vessels that carried Chinese goods abroad and low Chinese labor rates made it a very profitable enterprise.

Before China’s ban, only 9% of globally discarded plastics were being recycled and 12% were burned. The rest ended up in landfills or simply dumped into the environment. Over the coming decade, as many as 11 million tons of plastic will have to find a new place to be processed or otherwise disposed of. There is already evidence that plastic waste is accumulating in countries that are dependent on exporting. In many places, including a number of American cities, there are curtailed collections and new restrictions on what kinds of plastics are accepted.

Some experts are hopeful that China’s ban might actually have an upside if it leads to better solutions for managing the world’s waste. North America and Europe need to expand processing capabilities and manufacturers need to make their products more easily recyclable. Mostly, the Chinese ban should be a wake-up call to the world on the need to greatly reduce single-use plastics.

**********

Web Links

Piling Up: How China’s Ban on Importing Waste Has Stalled Global Recycling

Photo, posted August 8, 2017, courtesy of Sino-German Urbanisation Partnership via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Trees And The Future Of Cities

April 16, 2019 By EarthWise Leave a Comment

The shade of a single tree is a welcome source of relief on a hot summer day. But even a relatively small patch of woods can have a profound cooling effect. A new study at the University of Wisconsin-Madison looks at the role trees play in keeping towns and cities cool.

According to the study, the right amount of tree cover can lower daytime temperatures in the summer by as much as 10 degrees. The effects are noticeable from neighborhood to neighborhood and even on a block-by-block basis.

Cities are well-known to be hot spots due to the urban heat islanding effect. Using trees to keep temperatures more comfortable in cities can make a big difference for the people who live and work there.

The man-made structures of cities – roads, sidewalks, and buildings – absorb heat from the sun during the day and slowly release it at night. Trees, on the other hand, not only shade those structures from the sun, but they also transpire -or release water in the air through their leaves – which helps to cool things down.

According to the study, to get maximum cooling benefits, tree canopies must exceed forty percent, meaning that city blocks need to be nearly halfway covered by tree branches and leaves. To get the biggest bang for the buck, cities should start planting more trees in areas that are already near the forty percent threshold. But

trees can’t just be in parks. They need to be in places where people are active.

If we want the places where we live to be more comfortable and resilient in a warming world, we need to plant more trees.

**********

Web Links

Study suggests trees are crucial to the future of our cities

Photo, posted May 26, 2012, courtesy of Mislav Marohnic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Quiet Clean Energy Revolution

March 5, 2019 By EarthWise Leave a Comment

While the Trump administration seeks to prop up and promote use of fossil fuels, the country continues to move in the opposite direction. Last year was actually a pretty positive year for clean energy in the U.S.

In terms of public opinion, 70% of Americans surveyed believe the country should produce 100% of its electricity from renewable energy sources and more than half of survey respondents think renewables are a good idea even if they raise energy bills.

Companies in the U.S. purchased a record 6.43 gigawatts of renewable power, enough to power 1.5 million homes. The number of corporations entering into renewable energy deals doubled last year.

More than 300 U.S. cities, towns or counties have made commitments to climate action and, as of November, 99 cities have committed to 100% renewable energy, doubling the total from a year ago.

A number of gubernatorial candidates running on ambitious renewable energy platforms were elected in November including those in Illinois, Colorado, New Mexico, Maine and Nevada.

Utilities are responding to the growing demand for clean energy. Consumers Energy in Michigan plans to cut carbon emissions by 80% and stop using coal. Iowa-based MidAmerican Energy will become the first U.S. utility to source 100% of its electricity from renewable sources next year. Xcel Energy, one of the biggest utilities in the country, has committed to be 80% carbon-free by 2030 and go completely carbon-free by 2050.

The fossil fuel industry with its supporters in high places is still kicking and screaming, but there is no doubt that the U.S. energy system is changing, and the quiet clean energy revolution will only pick up more steam in 2019.

**********

Web Links

The US Underwent a Quiet Clean Energy Revolution Last Year

Photo, posted August 15, 2009, courtesy of Ken via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Examining Sea Level Rise

January 17, 2019 By EarthWise Leave a Comment

It’s no secret that sea levels along the East Coast of the United States are rising. But what’s less known is that the water isn’t rising at the same rate everywhere. As the climate continues to change, some cities may remain dry while others struggle to keep water out.

During the 20th century, sea levels rose about 18 inches near Cape Hatteras in North Carolina and along the Chesapeake Bay in Virginia. During that same time period, New York City and Miami experienced a 12 inch sea level rise, while the waters near Portland, Maine only rose 6 inches. According to a study recently published in the journal Nature, there’s an explanation for this.

The variation is a result of a phenomenon called “post-glacial rebound.” During the last ice age, huge sheets of ice once covered land areas in the Northern Hemisphere, including parts of the Northeast U.S. The weight of the ice weighted down the land like a boulder on a trampoline. At the same time, peripheral lands such as the U.S. mid-Atlantic coast rose up. As the ice melted, the previously weighted-down regions rebounded while the peripheral lands began to sink. While these ice sheets disappeared some 7,000 years ago, this see-sawing of post-glacial rebound continues to this day.

Researchers combined data from GPS satellites, tide gauges, and fossils in sediment with complex geophysical models to produce this comprehensive view of sea level change since 1900. While post-glacial rebound accounts for most of the sea level variation along the East Coast, researchers noted that when that factor is stripped away, “sea level trends increased steadily from Maine all the way down to Florida.”

**********