The short answer is no. No single hurricane or weather event can be directly linked to the general phenomena known as climate change. “Climate change does not cause things, because climate change is not a causal agent,” writes David Roberts on Vox.com. “‘Climate change’ is a descriptive term — it describes the fact that the climate is changing.”

That said, global warming likely did contribute to the severity of Harvey, and has created an overall climate more hospitable to the formation of extreme weather events of every stripe. "For hurricanes, we would ask the question as to what are the possible hurricane developments in the world we live in and compare that to the possible hurricane developments in a world without climate change," Dr Friederike Otto from the University of Oxford tells BBC News.

One definite “fingerprint” of global warming on Harvey is the intensity and amount of rainfall. Climatologists cite the Clausius-Clapeyron equation (a hotter atmosphere holds more moisture: for every extra degree Celsius in warming, the atmosphere can hold 7% more water) as one link between global warming and stronger storms. Houstonians have witnessed a 167 percent increase in the frequency of the most intense downpours since the 1950s.

Adam Sobel of Columbia’s Initiative on Extreme Weather and Climate estimates that as much as 10% of Harvey’s rainfall could be blamed on global warming, while Kevin Trenberth of the U.S. National Center for Atmospheric Research pegs the number at closer to 30%. “It may have been a strong storm, and it may have caused a lot of problems anyway—but [human-caused climate change] amplifies the damage considerably,” Trenberth reports in The Atlantic.

We’re also heating up our seas. "The waters of the Gulf of Mexico are about 1.5 degrees Celsius warmer above what they were from 1980-2010," reports Sir Brian Hoskins from the Grantham Institute for Climate Change. "That is very significant because it means the potential for a stronger storm is there.”

Meanwhile, even the fact that Harvey hung around so long and dumped rain on and around southeast Texas for nearly four days suggests a climate connection: A recent report from climate scientist Michael Mann suggests that near-stationary summer weather patterns are more common in a warmer world.

But others think we are focusing too much on the climate underpinnings of Harvey. Ilan Kelman of University College London’s Institute for Risk and Disaster Reduction tells the BBC that the real human contribution to the catastrophe in Houston is more about the type of development we allow than about the emissions we are pumping skyward. 

"The hurricane is just a storm, it is not the disaster," says Kelman. "The disaster is the fact that Houston population has increased by 40% since 1990 [and] that many people were too poor to afford insurance or evacuate.” He adds: "Climate change did not make people build along a vulnerable coastline so the disaster itself is our choice and is not linked to climate change."

CONTACTS: U.S. National Center for Atmospheric Research, ncar.ucar.edu/; Initiative on Extreme Weather and Climate, extremeweather.columbia.edu/; “Influence of Anthropogenic Climate Change on Planetary Wave Resonance and Extreme Weather Events,” www.nature.com/articles/srep45242.

 

Unfortunately, our beloved dogs and cats do produce shockingly high amounts of greenhouse gases that contribute to climate change. According to a recent study by UCLA Professor Gregory Okin, American dogs and cats generate the equivalent of almost 64 million tons of greenhouse gas emissions (primarily in the form of methane and nitrous oxide) per year, an amount equivalent to driving 13.6 million cars for a year.

Besides all of this off-gassing, our cats and dogs are also big meat eaters, which doesn’t help their carbon footprints. Cats and dogs consume about 20 percent as many calories as people do in the U.S.—or about as much as 62 million Americans. And because our pets are mainly meat eaters, they account for some 30 percent of the animal-derived calories compared to what you and I consume.

So what’s the big deal? In short, raising livestock requires significantly more land, water and energy than growing plants. A recent report by the Worldwatch Institute goes so far as to say that some 51 percent or more of greenhouse gas emissions are caused by animal agriculture. Since we like to feed our pets meat-based dog and cat food, Fido and Buttons are guilty by the ripple effect. Meat used in dog and cat food generally comes from the scraps of meat that humans eat.

Another reason why dogs and cats are contributors to climate change besides their diets is by virtue of all that...feces. The U.S. Environmental Protection Agency (EPA) even categorizes dog waste as a non-point source pollutant, which places it alongside harmful chemicals such as herbicides and insecticides. 

Meanwhile, cat litter can contain toxins that are harmful to the environment and even human health. Clay, a common ingredient in most cat litters, must be “strip mined,” a process that has already destroyed millions of acres of land across Appalachia and beyond. Many kitty litter companies also use silica gel in their formulations to absorb and deodorize smells—despite the fact that the International Agency for Research on Cancer classified it as a known human carcinogen back in 1997. And those cats that just go outside aren’t doing the environment any favors either, as cat feces can be toxic to ground soil.

There is no clear or easy solution to this ongoing problem. But little changes can help. For example, try switching your pet over to a plant-based diet — perhaps after a discussion about the options with your veterinarian. After all, you want to make sure your pet is getting enough protein in its vegetarian diet to live an active, happy and healthy life. 

If you’re not willing to turn your pet to outright vegetarianism, you can work in more and more vegetarian food over time. Also, you can still be part of the solution by at least buying organic pet food and compostable cat litter. These few changes might not automatically solve the worldwide problem, but at least you—and Fido and Buttons—will be taking a few steps, er, paw prints, in the right direction.

CONTACTS: EPA’s Pet Car Fact Sheet, https://goo.gl/JX2UXt; “Environmental impacts of food consumption by dogs and cats,” https://goo.gl/4Zykhr.

Yes and no, depending on how much imperfection you’re willing to tolerate. Calorie-for-calorie, an acre of land can feed more mouths growing vegetables and grains for direct human consumption that it can growing feedstock for farm animals that end up on our plates.

But for years beef industry defenders have pointed to the “carbon sequestration” benefits of grazing cattle on grasslands as an environmental justification for continuing to raise and sell livestock. According to the theory, grasslands around the world hold the potential to store (sequester) enough atmospheric carbon dioxide (CO2) to reverse global warming if they are used to graze livestock “bunched and moving, as a proxy for former herds and predators”—in the words of “holistic management” guru Allan Savory—to mimic what were once naturally-occurring processes in nature. Since grasses, like all plants, consume (and then store) atmospheric CO2—a key component of photosynthesis—to grow to full maturity, using grassland to graze cattle helps sequester untold amounts of greenhouse gases as new grasses shoot up after the livestock has passed through.

But a recent analysis by Tara Garnett and researchers at Oxford’s Food Climate Research Network found that the carbon sequestration benefits of even “holistic management”-based livestock grazing are limited at best. They concluded that, even under “very generous assumptions,” livestock grazing could only offset 20-60 percent of the average annual greenhouse gas emissions of grass-fed beef—and only between 0.6 and 1.6 percent of total annual greenhouse gas emissions. This last figure is the real clincher, given that livestock account for some 18 percent of global greenhouse gas emissions all told.

Livestock agriculture—grass-fed or otherwise—is already a big contributor to global warming purely as a result of methane gas “emissions” from cattle. (Methane is an even more potent greenhouse gas than CO2.) All of this cattle belching and flatulence, combined with millions of tons of off-gassing manure generated on farms around the world, combine to make animal agriculture responsible for 35-40 percent of annual “anthropogenic” (human-caused) methane emissions worldwide. 

And it turns out that grass-fed cattle actually generate significantly more methane than their feedlot-held counterparts due to how difficult it is to digest wild grasses versus the corn- and soy-based feed offered back in the barn. Meanwhile, agricultural researchers are working on ways to reduce methane emissions even further for feedlot cattle by adding chemical and biological agents into feed that cancel out the “methanogenic” microorganisms that lead to intestinal production of so much methane in the first place.

That said, environmentalists warn that we shouldn’t rely on such “interventions” when we can solve our problems the old-fashioned way: Reducing your overall intake of meat, if not going vegetarian or vegan altogether, is the only way to guarantee that our meat addiction doesn’t kill us in the end.

CONTACTS: Food Climate Research Network, www.fcrn.org.uk; “Restoring The Climate Through Capture And Storage Of Soil Carbon Through Holistic Planned Grazing,” The Savory Institute, www.savory.global/wp-content/uploads/2017/02/restoring-the-climate.pdf; “Carbon, Methane Emissions and the Dairy Cow,” Penn State Extension, https://extension.psu.edu/carbon-methane-emissions-and-the-dairy-cow.

While it may be the fastest and most convenient way to go long distances, air travel remains the most environmentally-unfriendly mode in our mix of transportation options. Airplanes require massive amounts of petroleum-based fuel that deposits greenhouse gas emissions directly into the atmosphere (where they’re two to four times more potent in causing global warming than equivalent ground-level emissions). The UN’s Intergovernmental Panel on Climate Change (IPCC) reports that aviation is responsible for some 3.5 percent of human-caused global warming to date and expects that figure to grow to somewhere in the five to 15 percent range by 2050 if we don’t take action soon to curb emissions.

Fortunately, the aviation industry hasn’t been hiding its head in the sand. New planes coming off assembly lines at Boeing and Airbus, the world’s two biggest jet manufacturers, are about 15 percent more efficient than previous models. Deploying next generation engines that can produce more thrust with less fuel is one way in which airplane makers are boosting efficiency. Another is through the use of lighter materials, with carbon fiber replacing metal in many applications and 3D printing of lightweight titanium parts taking the place of forged or machined aluminum. 

Better design is also contributing to the optimization of fuel efficiency. One example is the winglet, a small vertical projection retrofitted on the tip of the wing that can cut emissions some six percent by reducing drag. Less than 20 percent of the world’s jets have them now; spreading the technology widely could significantly boost the overall fuel efficiency of aviation.

We can expect to see even more dramatic gains when so-called blended wing-body (BWB) designs go mainstream. Thanks to their broader wings and the resulting higher “lift-to-drag” ratio, these futuristic planes are significantly more aerodynamic than conventional jets. The Air Transport Action Group (ATAG), a non-profit focusing on sustainable development in aviation, reports that these BWB-design planes can go as far and as fast as conventional jets on 75 percent of the fuel. But don’t hold your breath: Researchers don’t expect BWB planes to be ready for commercial use for another two decades.

There is also considerable R&D going into greening the fuel side of the equation. Illinois-based General Biomass, for instance, is developing carbon-neutral jet fuel formulations derived from the seed oil of jatropha and camelina plants. And Texas’s Neste is a leader in developing “recycled jet fuel” made from the residue of used diesel fuel. 

And as in the auto industry before it, aviation is now abuzz with talk of hybrid-electric and all-electric planes. Seattle-based Zunum Aero plans to have a prototype of its hybrid-electric 19-seater commuter plane ready for test flights by 2020, and hopes to start supplying airlines soon thereafter with commercial-grade models. Meanwhile, Silicon Valley’s Wright Electric is collaborating with Europe’s easyJet in developing a new battery-powered aircraft designed for short hop commuter routes. These new all-electric planes, which should be ready for prime time within a decade, will be 10 percent cheaper for airlines to buy and operate than traditional jets—and without the emissions stigma.

CONTACTS: IPCC, ipcc.ch; Boeing, boeing.com; Airbus, airbus.com; ATAG, atag.org; General Biomass, generalbiomass.com; Neste, neste.com; Zunum Aero, zunum.aero; Wright Electric, weflywright.com; easyJet, easyjet.com.

Children are affected by the same environmental hazards as adults, only they’re more vulnerable given their smaller size and the fact that their bodies are still developing. According to the World Health Organization (WHO), harmful exposures can start as early as in utero.

“Proportionate to their size, children ingest more food, drink more water and breathe more air than adults,” reports WHO. “Additionally, certain modes of behavior, such as putting hands and objects into the mouth and playing outdoors can increase children’s exposure to environmental contaminants.”

Some of the most common contaminants we should be vigilant about avoiding include pesticides (in foods), lead (in old paint), asbestos (in insulation and construction materials), BPA (in plastic food/drink containers and the lining of cans), PFCs (in non-stick cookware, carpeting and mattresses) and flame retardants (in furniture and drapery). And, of course, many branded household cleaners contain potentially hazardous ingredients (bleach, ammonia, diethanolamine, triethanolamine) as well.

Given how common these elements are in today’s world, keeping kids safe isn’t an easy task. For starters, choose organic food and drink whenever possible to cut down on the pesticides your kids ingest. While pesticides work well to keep away the bugs that can ruin harvests, they also can cause neurological and reproductive problems for humans who ingest traces of them. Apples, celery, strawberries, peaches, spinach, nectarines, grapes, bell peppers, potatoes, blueberries, lettuce and kale/collard greens are the worst offenders in the produce aisle, according to the Environmental Working Group (EWG), so definitely spring for organic versions of these particular fruits and veggies. Packaged and processed foods likely contain plenty of pesticide residues, too, unless they are marked as certified organic.

To avoid household cleaners, the Organic Consumers Association (OCA) recommends ditching the expensive specialized products that likely contain harmful chemical additives. “A few safe, simple ingredients like soap, water, baking soda, vinegar, lemon juice and borax, aided by a little elbow grease and a coarse sponge for scrubbing, can take care of most household cleaning needs.” Look for specific formulations on organicconsumers.org, as well as links to some environmentally friendly name-brand household cleaners.

While there is less we can do individually about air pollution if we want our kids to spend time outdoors, at the macro level we can all help by driving our cars less and turning down our thermostats (to reduce the emissions we cause) and ordering less stuff online (to cut down on air pollution from shipping).

Parents, teachers and caregivers should educate themselves about what to avoid and become expert label readers so they can make health-smart choices. Meanwhile, the U.S. Centers for Disease Control & Prevention (CDC) is urging pediatricians to take a greater interest in the environmental impacts on the health of their patients and discuss with parents how to keep kids safe in and around the home, the neighborhood, and at school.

CONTACTS: WHO, www.who.int; EWG, www.ewg.org; OCA, www.organicconsumers.org; CDC, www.cdc.gov.