Climate Change – Everything you need to know about
What is Climate Change
Our planet’s weather patterns are undergoing a long-term shift, affecting climates everywhere – from your local area to the entire globe. This shift, known as climate change, is causing a variety of noticeable effects.
The main culprit behind this change is human activity, especially the burning of fossil fuels. These fuels release heat-trapping gases into the atmosphere, warming Earth’s surface. While natural phenomena like El Niño and volcanic eruptions can also influence climate, human activity is currently the overwhelming force.
Differences between weather vs. climate
Climate is like a person’s overall personality – it’s the long-term average weather conditions in a region, typically spanning at least 30 years. This includes factors like temperature, humidity, and rainfall patterns across seasons and decades. A more precise definition describes climate as the average state of these weather elements, along with how much they naturally fluctuate over time.
Weather, on the other hand, is like a person’s mood swings – it’s the day-to-day state of the atmosphere. It’s what you experience when you check the forecast – is it sunny, rainy, or windy today?
While both climate and weather involve change, they happen on very different scales. Weather can change rapidly, within hours or days. Climate, however, changes much more slowly, although it’s not entirely fixed. It can vary over long periods, from daily cycles to even millions of years.
Earth’s Symphony: How the Atmosphere Plays with Others
The atmosphere isn’t a solo act. It’s part of a grand Earthly orchestra, interacting with the oceans, ice caps, land, and even plants in a complex dance. All these elements make up a single, interconnected system.
For example, climate tells vegetation where to party. Deserts love hot, dry areas, while forests thrive in humid regions. But plants aren’t just passive listeners. They play their own instruments too! They reflect sunlight back into the atmosphere, like bouncing a beach ball. They also move water (and its hidden heat) from the ground up, adding moisture to the air. And by their very presence, they influence how air flows across land.
It’s a beautiful give-and-take: climate shapes where plants live, and plants, in turn, influence climate. This intricate interplay keeps Earth’s symphony in tune.
What Is Global Warming?
It’s important to distinguish this from “climate change.” While related, global warming is specifically about rising temperatures. Climate change is the broader term encompassing this warming trend and its effects on weather patterns, precipitation, and ecosystems.
The effects are significant. Since the Industrial Revolution, human activity has already raised Earth’s average temperature by 1 degree Celsius (1.8 degrees Fahrenheit), and it’s climbing fast. This warming is unprecedented in thousands of years, and scientists are confident it’s due to human activity.
Evidence of global warming
Earth’s climate has changed throughout history. Over 800,000 years, the Earth has been swung between eight cycles of ice ages which ended about 11,700 years ago marking the beginning of the modern climate era — and of human civilization. What drives these climate swings? Surprisingly, small variations in Earth’s orbit around the Sun affected the amount of solar energy reached our planet, influencing temperatures over long periods.
Our Planet’s Changing Climate: A Look at the Evidence
The Earth’s climate is undeniably shifting. Here’s a closer look at some key signs:
Global Temperature Is Rising
The average global temperature has climbed a significant 2 degrees Fahrenheit (1 degree Celsius) since the late 19th century. This warming has accelerated in recent decades, with the seven hottest years on record all occurring since 2016.
The Ocean Is Getting Warmer
Our oceans are like giant heat sponges, absorbing most of this extra warmth. This has caused a measurable rise in water temperatures, particularly in the top 100 meters (about 328 feet) of ocean showing warming of 0.67 degrees Fahrenheit (0.33 degrees Celsius) since 1969, Earth stores 90% of the extra energy in the ocean.
The Ice Sheets Are Shrinking
The Greenland and Antarctic ice sheets, crucial for regulating sea levels, are losing mass at an alarming rate. Data from NASA’s Gravity Recovery and Climate Experiment show Greenland lost an average of 279 billion tons of ice per year between 1993 and 2019, while Antarctica lost about 148 billion tons of ice per year.
Glaciers Are Retreating
Glaciers around the world, from the Alps to the Andes, are rapidly shrinking. This melting trend contributes to rising sea levels.
Snow Cover Is Decreasing
Satellite observations reveal that the amount of spring snow cover in the Northern Hemisphere has decreased over the past five decades and the snow is melting earlier.
Sea Level Is Rising
Global sea levels have risen about 8 inches (20 centimeters) in the past century. This rate in the last two decades, however, is nearly double that of the last century and accelerating slightly every year. This rise threatens coastal communities and ecosystems.
Arctic Sea Ice Is Declining
The Arctic sea ice, a critical climate regulator, is shrinking dramatically in both extent and thickness.
Extreme Events Are Increasing in Frequency
The number of record high temperature events in the United States has been increasing, while the number of record low temperature events has been decreasing, since 1950. The U.S. has also witnessed increasing numbers of intense rainfall events.
Ocean Acidification Is Increasing
Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30%. This increase is due to humans emitting more carbon dioxide into the atmosphere and hence more being absorbed into the ocean. The ocean has absorbed between 20% and 30% of total anthropogenic carbon dioxide emissions in recent decades (7.2 to 10.8 billion metric tons per year).
The Causes of Climate Change
Human activities are driving the global warming trend observed since the mid-20th century.
A simplified animation of the greenhouse effect. Credit: NASA/JPL-Caltech
Increasing Greenhouses Gases Are Warming the Planet
The burning of fossil fuels like coal and oil over the past century is the driving force behind climate change, responsible for 75% of greenhouse gas emissions and nearly 90% of carbon dioxide emissions specifically.
Why such a high number? It’s all about the burning process. When we burn fossil fuels, we essentially combine the carbon stored within them with oxygen in the air. This chemical reaction creates carbon dioxide (CO2), a major greenhouse gas that traps heat in the atmosphere, causing our planet to warm.
While land clearing for various purposes such as agriculture, industry, etc. also contributes to greenhouse gases, it pales in comparison to the massive impact of fossil fuel burning.
Generating power
Burning fossil fuels: Generating electricity and heat through coal, oil, or gas releases heat-trapping gases like carbon dioxide and nitrous oxide. While cleaner options like wind and solar power are growing, they still represent only 25% share of global energy production.
Buildings: Our homes and workplaces consume significant energy, often from fossil fuel sources, for heating, cooling, and appliances. This energy use translates to greenhouse gas emissions.
Transportation:
Fossil fuel vehicles: Cars, trucks, ships, and airplanes largely rely on fossil fuels, making transportation a major source of emissions, particularly carbon dioxide.
Manufacturing:
Fossil fuel reliance: Many industrial processes, including the manufacturing of everyday goods like electronics, clothes, and plastics, depend on fossil fuels for energy. This dependence contributes to greenhouse gas emissions.
Land Use:
Deforestation: Clearing forests releases the carbon they store, reducing nature’s ability to absorb greenhouse gases. Agriculture and land-use changes also contribute significantly to emissions.
Food Production:
Agricultural practices: Raising livestock (methane emissions from digestion), using fertilizers, and clearing land for agriculture all contribute to greenhouse gas emissions. Food packaging and distribution also add to the impact.
Consumption Habits:
Excessive consumption: Our overall consumption patterns, from the energy used to make things to how much we throw away, contribute to emissions. This includes buying excessive amounts of clothing, electronics, and other goods.
Current Global Warming Cannot Be Explained by Solar Irradiance
Scientists track the energy Earth receives from the Sun using a measure called Total Solar Irradiance (TSI). This takes into account both the Sun’s natural 11-year cycle of ups and downs, and even powerful bursts like solar flares.
While solar activity has influenced past climate changes – for instance, a period of low solar activity combined with volcanic eruptions is linked to the Little Ice Age – it’s not the main driver behind the current warming trend. Here’s why:
Sun’s Output Not Increasing: Measurements show TSI hasn’t significantly increased in recent decades, despite rising global temperatures.
Warming Pattern Doesn’t Match: If the Sun were the main culprit, we’d expect warming throughout the atmosphere. However, observations show warming concentrated in the lower atmosphere, with the upper atmosphere actually cooling. This points to a different culprit – greenhouse gas trapping heat.
Several key pieces of evidence point away from the Sun being the main driver of current global warming:
Flat Sun Output: Measurements of the Sun’s energy output (Total Solar Irradiance) show it hasn’t significantly increased in recent decades, despite rising global temperatures.
Uneven Heating Pattern: If the Sun were the main culprit, warming would be happening throughout the entire atmosphere. However, scientists observe warming concentrated near Earth’s surface and lower atmosphere, with the upper atmosphere actually cooling. This pattern is consistent with heat being trapped by greenhouse gases in the lower atmosphere, not the Sun directly heating everything.
Climate Model Confirmation: Sophisticated climate models that take into account changes in solar irradiance struggle to replicate the observed warming trend over the past century without including the factor of increasing greenhouse gases.
The Effects of Climate Change
Climate change isn’t a distant threat – it’s happening now, and its effects are already being felt around the world. Here’s a closer look at some of the key consequences we’re facing:
- Heating Up: Global temperatures are on the rise, with the last decade being the hottest on record. This translates to more heatwaves, making outdoor work difficult and increasing heat-related illnesses.
- Extreme Weather on the Rise: Storms are becoming more intense and frequent, fueled by rising temperatures and increased moisture evaporation. This leads to devastating floods, stronger hurricanes, and destructive droughts.
- A Warming Ocean: The ocean absorbs much of the Earth’s heat, causing sea levels to rise and threatening coastal communities. Ocean acidification, caused by increased carbon dioxide absorption, harms marine life and coral reefs.
- Loss of Biodiversity: Climate change is pushing species towards extinction at an alarming rate. Rising temperatures, wildfires, extreme weather events, and invasive species are all contributing factors.
- Food Security Threatened: Changes in climate and extreme weather events disrupt food production, impacting crops, livestock, and fisheries. This leads to hunger and malnutrition, especially in vulnerable regions.
- Health Risks on the Rise: Climate change is the biggest health threat we face. It worsens air pollution, expands the range of diseases, increases deaths from extreme weather events, and puts pressure on mental health due to displacement and food insecurity.
- Poverty and Displacement: Climate change exacerbates poverty, with floods destroying homes and livelihoods, and droughts impacting agriculture. Millions are displaced each year due to extreme weather events, further increasing vulnerability.
A Regional Breakdown of Impacts in the US
The effects of climate change are far-reaching, impacting different regions of the US in unique ways. Here’s a summary of current and future challenges based on the Third and Fourth National Climate Assessment Reports:
Northeast:
- Heatwaves, downpours, and rising sea levels: These factors threaten infrastructure, agriculture, fisheries, and ecosystems. While farmers may explore new crops, these adaptations come with costs and risks. Additionally, not all areas have the resources to adapt quickly enough. However, some states and cities are taking proactive steps by incorporating climate change into their planning.
Northwest:
- Water woes: Changes in river flow patterns are reducing water availability, creating competition for this vital resource. Sea level rise, erosion, flooding, and increasing ocean acidity further threaten the region. Wildfires, insect outbreaks, and tree diseases are also on the rise, leading to widespread forest loss.
Southeast:
- Sea level rise: This poses a constant and growing threat to the region’s economy and environment. Extreme heat will negatively affect human health, energy production, and agriculture. Decreasing water availability will also have significant economic and ecological consequences.
Midwest:
- Extreme weather events: Heatwaves, heavy downpours, and flooding will have widespread impacts on infrastructure, health, agriculture, forestry, transportation, and air/water quality. Climate change also poses a range of threats to the Great Lakes.
Southwest:
- Heat, drought, and wildfires: These factors are already increasing, with wildfires becoming more frequent and severe. The warming climate also leads to water scarcity, reduced agricultural yields, and heat-related health issues in cities. Coastal areas face additional concerns like flooding and erosion.
Net Zero: Our Shot at a Livable Climate
What is Net Zero?
Imagine a world where the greenhouse gas emissions we create are balanced by what’s naturally removed from the atmosphere. That’s the essence of net zero. Here, any remaining emissions are captured and stored permanently, leaving a net balance of zero in the atmosphere.
Why is Net Zero Important?
Science is clear: to avoid the harshest consequences of climate change and ensure a livable planet for future generations, we need to limit global warming to 1.5°C above pre-industrial levels. Unfortunately, Earth is already about 1.1°C warmer, and emissions continue to rise.
The Paris Agreement, a global pact on climate change, calls for a dramatic reduction in emissions – 45% by 2030 and net zero by 2050 – to keep warming below 1.5°C.
The Path to Net Zero: A Transformation
Achieving net zero is a monumental challenge, requiring a complete overhaul of how we produce energy, consume goods, and travel.
The energy sector is a major culprit, responsible for roughly three-quarters of greenhouse gases today. Replacing fossil fuels like coal, oil, and gas with clean energy sources like wind and solar power can significantly reduce emissions.
A Global Movement Takes Shape
Thankfully, we’re not alone in this fight. A growing alliance of countries, cities, businesses, and institutions are pledging to reach net zero. Major emitters like China, the US, India, and the European Union are among the over 140 countries committed, covering nearly 90% of global emissions.
Beyond national efforts, thousands of companies, cities, educational institutions, and financial institutions have joined the Race to Zero, vowing to halve global emissions by 2030.
Turning Pledges into Action
While the surge in net-zero commitments is encouraging, ensuring these promises translate into real action is crucial. To address this, the UN established a High-Level Expert Group in 2022 to develop stricter and clearer standards for net-zero pledges by non-state entities.
Are We on Track?
Unfortunately, current government commitments fall short. Existing national climate plans under the Paris Agreement would lead to a nearly 9% increase in emissions by 2030, compared to 2010 levels. This is far from the 45% reduction needed by 2030.
Reaching net zero by 2050 requires all governments, especially major emitters, to significantly strengthen their climate pledges (NDCs) and take immediate steps to cut emissions now.
Blue Lobster
Blue Lobster is your one-stop shop for understanding and reducing your carbon footprint. Available on iOS and Android, this app empowers you to:
- Track Your Carbon Footprint: See exactly how your daily activities contribute to greenhouse gas emissions.
- Benchmark Your Impact: Compare your footprint to regional and global averages to understand your impact relative to others.
- Reduce Your Emissions: Blue Lobster provides personalized recommendations for lowering your carbon footprint through everyday choices.
- Offset What You Can’t Cut: For unavoidable emissions, the app helps you discover credible carbon offset programs to balance your impact.
References:
https://climate.nasa.gov/evidence/
https://climate.nasa.gov/what-is-climate-change/
https://www.un.org/en/climatechange/what-is-climate-change