What do you actually know about climate change?

Breaking down the complicated topic from top to bottom

Most people say that they care about the environment, but many don’t fully understand the details of climate science. For example, 43% of Americans believe that plastic bottles and bags are a major contributor to global warming, which is incorrect. It’s not necessary for people to understand all of the nuances of the topic; however, we should understand it at a high level so that we can take appropriate actions.

Questions to answer

• What is it?
• Why is it important?
• Who is causing it?
• What is causing it?
• What can we do about it?
• How quickly do we need to act?
• Why is it difficult to take action?

What is it?

Climate change is caused by global warming, which is the gradual heating of Earth’s surface, oceans and atmosphere

• It occurs when CO2 and other air pollutants collect in the atmosphere and absorb heat that has bounced off the earth’s surface
• It is caused by human activity, primarily the burning of fossil fuels that pump carbon dioxide, methane and nitrous oxide into the atmosphere
• All of the largest international scientific organizations agree that global warming is real and has been caused by human action

Data from 2018

Why is it important?

Climate change will significantly impact humans and animals throughout the world

Extreme weather events

• More frequent and intense heat waves, droughts, fires, blizzards, rainstorms and hurricanes
• Agriculture systems will suffer, which could lead to famines
• Property will be destroyed, which could lead to economic hardship

Ice melt

• Melting ice reduces the inhabitable terrain for many animal species
• It also leads to sea level rise, which poses threats to coastal regions
• Scientists estimate that sea levels will rise 3 feet by 2100

Ocean acidification

• CO2 partially dissolves in ocean water, which produces carbonic acid
• Acid kills coral reefs and dissolves the shells of sea creatures
• Scientists estimate that all coral reefs will be gone by 2100

Warmer surface temperature

• Animals will be forced to migrate away from the equator and many species will not be able to compete in their new environments, leading to extinction
• The range of many deadly pathogens will expand, killing off plant and animal species that were formerly protected from disease
• Scientists estimate that half of all plant species and one third of all animal species will be extinct by 2100

Who is causing it?

Most greenhouse gases come from China, United States, EU, India, Russia and Japan. China currently produces the most emissions, but the United States has historically produced the most emissions

Data from 2017

The United States produces the most emissions per person

Data from 2017

What is causing it?

Here are the sources of emissions in the United States:

Data from 2018

“Buildings” refers to homes and commercial businesses

Data from 2016

“Production” refers to the development of goods and raw materials

Data from 2018

“Transportation” refers to the movement of people and goods

Data from 2017

“Agriculture” refers to crop and livestock production for food

Data from 2018

The charts above are just for United States emissions. The breakdown for global emissions looks similar, but there is less impact from transportation and more impact from deforestation

Data from 2016

Plants absorb CO2 from the atmosphere as they grow and store some of this carbon throughout their lifetime. The US has planted more trees than it has removed so it is not considered a source of emissions. However, many countries clear large areas of forest land for agricultural purposes or for settlements, which results in more CO2 trapped in the atmosphere.

What can we do about it?

We will need to make significant changes across many aspects of our life in order to significantly reduce emissions. Here are some things that individuals can do:

Use renewable energy for home electricity

• Switch to rooftop solar panels. They are 50–75% cleaner than electricity from power plants, depending on where you live
• Impact = High
• Cost = High

Use a more efficient heating and A/C system

• Switch to a heat pump system. They are 33% more efficient than furnace or boiler systems
• Impact = Medium
• Cost = Medium

Use less heating and A/C

• Switch to a smart thermostat. They are 15% more efficient than traditional thermostats
• Impact = Low
• Cost = Low

Drive a more fuel efficient car

• Switch to an electric car. They are 75–100% cleaner than gas powered cars, depending on where the electricity comes from
• Impact = High
• Cost = High

Drive less often

• Bike or take public transit more often. On average, subways and metros are 75% cleaner than gas powered cars
• Impact = Medium
• Cost = Free

Invest in renewables and divest from fossil fuels

• Invest in funds that exclude dirty energy companies by default. Use this online tool to find out the fossil fuel exposure of your mutual funds
• Impact = Medium
• Cost = Free

Eat food with lower emissions

• Stop eating beef. Cows produce 6x more emissions than pigs or chickens
• Impact = High
• Cost = Free

The changes mentioned above are helpful, but the biggest impact that you can have is voting and donating to help influence environmental policies. The government can make significantly more impact than any individual actions. Here are some things that the United States government can do:

Switch to renewable energy for electricity production

• Wind. Pros: doesn’t require lots of land/space, enormous potential. Cons: power output fluctuates
• Hydroelectric. Pros: consistent power output. Cons: disruptive to natural ecosystems, limited potential
• Solar. Pros: deployable at the consumer level, unlimited potential. Cons: requires lots of land/space, power output fluctuates
• Biomass (plants). Pros: consistent power output, unlimited potential. Cons: recurring operational costs, requires lots of land/space
• Geothermal. Pros: consistent power output. Cons: limited potential

Data from 2019

Increase tax incentives for “clean” products

• Rooftop solar and energy-efficient HVAC systems. Current incentives: 30% credit for heat pumps and solar panels
• Electric vehicles. Current incentives: up to $7500, depending on the car maker

Increase tax penalties for “dirty” products

• Coal. Current penalties: ~4% of selling price
• Oil. Current penalties: ~20% of selling price
• Beef. Current penalties: none

In addition to lowering emissions, we can also remove CO2 from the atmosphere. There are several methods for carbon capture, but each has significant challenges

Forests

• Trees remove carbon from the air via photosynthesis. Every acre of land restored to temperate forest can sequester about 3 metric tons of CO2 every year
• Cost = $50 per metric ton
• This solution requires lots of land, which could conflict with food production needs. Trees also take a long time to grow so the effects are not immediate

Farms

• Fertile soil can store carbon via decomposition and soil respiration. Covering land with plants during off seasons (cover crops) and using compost can increase soil efficiency. Every acre of land that is handled properly can sequester about 1 metric ton of CO2 every year
• Cost = $75 per metric ton
• This solution is challenging because farmers are not always incentivized to make changes. It’s also difficult to implement due to the variability of agricultural lands

Direct air capture

• New technology can remove carbon directly from the atmosphere
• Cost = $150 per metric ton
• This technology requires significant energy, which would need to be renewable in order to have a net impact. The renewable energy could instead be used to reduce emissions

How quickly do we need to act?

We have already warmed the Earth by about 1 degree Celsius. In order to avoid disastrous consequences for our environment, scientists estimate that we need to limit the average global temperature increase to 1.5 degrees Celsius

If we increase global temperature by 2 degrees Celsius instead of 1.5 degrees, many consequences will be significantly worse

To achieve this 1.5 degrees goal, we need to cut current emission rates in half by 2030 and reach net-zero emissions by 2050. We have consistently increased global emissions for the past 30 years so this reduction will be unprecedented

We need to act soon because greenhouse gases do not go away quickly. Scientists estimate that CO2 lasts for hundreds of years in the atmosphere. Methane lasts for 12 years and nitrous oxide lasts for 114 years

Why is it difficult to take action?

It seems fairly obvious that we should reduce emissions and that we need to act quickly. However, there are several reasons why it is challenging to make changes:

Political

• Fossil fuel companies spend billions of dollars each year to lobby and support political candidates that will benefit them. Oil and gas companies spent over $100 million in 2016 to help steer election results. They are able to donate this amount of money because our corporate donation rules have obvious loopholes and are easy to bypass

Economic

• Clean energy solutions often require a large upfront upfront investment, which isn’t possible for some people. Electric cars cost ~$40k, rooftop solar costs ~$15k, and a new HVAC system costs ~$5k
• Once a dirty energy plant is constructed, the economics create an incentive for it to continue operating. Companies invest a large amount of money upfront, which takes a long time to pay off. Additionally, thousands of people may become reliant on the facility for jobs so shutting it down becomes difficult

Social

• Most people do not fully understand global warming and the threats that it poses. In fact, some people don’t believe in global warming at all. Education is crucial in order for people to start taking action
• People aren’t able to see the effects of their actions. The impact of global warming will be immense, but it will happen gradually over several decades. It’s difficult to grasp the severity of the situation since it isn’t an immediate threat

Technological

• Producing large amounts of electricity through solar and wind means that the energy will fluctuate significantly. Because of this, we need to be able to store the energy and distribute it efficiently on a massive scale. Our current battery technology isn’t advanced enough to handle a full switch to renewable energy

Although we face a difficult challenge with many roadblocks, it’s definitely still possible to reach our goal of limiting the global temperature increase to 1.5 degrees Celsius. It will require a collective effort from individuals and governments around the world though. To kickstart this movement, people need to be educated about global warming. Please share this post with others if you find it useful!