Climate Change: Fundamental Concepts
Climate change is an undeniable reality that surrounds us. It manifests itself in many forms, from extreme weather events and the gradual melting of polar ice sheets to the declining health of the world's great forests and its effects on the biosphere. As we navigate the Anthropocene era, characterized by the profound influence of human activities on our planet, it is worth to revisit the fundamentals of climate change and to refresh the case for collective action to mitigate its impacts.
The Changing Atmosphere and Greenhouse Gases
One of the most critical aspects of climate change is the alteration of the Earth's atmosphere due to the release of greenhouse gases. These gases, primarily carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), trap heat from the sun and cause a warming effect. Importantly, and quite amazingly in fact, humans have only begun tracking the composition of these gases in a scientific way in the atmosphere since the 1950s. It was then when scientists realized that the accumulation of gases in the atmosphere will amplify the greenhouse effect, leading to what is now called “global warming”
In 2019, atmospheric CO2 concentrations reached an annual average of 410 ppm, which is higher than at any time in at least 2 million years, while concentrations of CH4 (methane) were 1,860 ppb and of nitrous oxide were 332 ppb, which were higher than at any time in the last 800,000 years.
As the planet’s atmosphere becomes warmer, it leads to increased heatwaves and more extreme rainfall events. Warmer air has the capacity to hold more water vapor, intensifying weather patterns. Earth’s global average surface temperature in 2011–2020 was around 1.1 °C higher than the pre-industrial average.
Additionally, changes in the atmosphere's composition have dynamic effects on weather systems, altering their movement and development. Extreme weather events that were once rare become more common in this warmer world. Human activities, such as burning fossil fuels and deforestation, significantly contribute to the rise in greenhouse gas concentrations: humans have essentially been using - and are using - the sky as an open sewer to continually discharge gases and residue from industrial processes. And as I touched on in my Introduction to Environmental Science article, there is no away: everything is contained and circulates in the natural world.
Polar Ice Sheets and Rising Sea Levels
The Earth’s polar ice sheets, particularly those in Antarctica and Greenland, play a vital role in regulating global climate and sea levels. Satellite technology has enabled us to monitor these ice sheets closely, revealing alarming trends. Over the past few decades, there has been a sixfold increase in ice mass loss compared to the 1990s.
The sheer size of these ice sheets is staggering, with ice layers thousands of meters thick. The West Antarctic ice sheet, in particular, is of concern because a portion of it sits below sea level. If this ice sheet were to lift off the seabed and melt, it would contribute significantly to rising sea levels, which have already increased by approximately 20 centimeters since the 1980s.
The Crucial Role of Forests and the Biosphere
Forests, often referred to as the Earth's lungs, are critical in the fight against climate change. They absorb carbon dioxide, release oxygen, and help moderate weather systems. Tropical forests, which cover approximately 50% of the land biosphere, are especially vital for maintaining global climate stability.
The interconnectedness of Earth's systems is evident, and tiny changes in one component can trigger larger impacts across the planet. The land biosphere alone absorbs about 25% of carbon dioxide emissions from fossil fuels, contributing to the regulation of global climate. Ecosystems can become accelerators, creating feedback loops that exacerbate climate change. This highlights the importance of preserving and restoring our forests and natural habitats.
The Anthropocene Era: A Geological Transformation
The concept of the Anthropocene marks a significant shift in our understanding of Earth's history. For roughly 10,000 to 20,000 years, human history unfolded within the Holocene epoch, following the last ice age. However, the Holocene has now given way to the Anthropocene, an era defined by humanity's profound impact on the planet: a single life species, humans, are now responsible for change made to the planet on such a scale that it deserves its own name.
The realization of climate change, particularly the increase in atmospheric CO2 concentrations since the 1950s, was one of the earliest signals of this new epoch. It shattered the notion that the sky was an infinite repository for waste. The industrial revolution accelerated the rise in CO2 levels, with current concentrations exceeding 415 parts per million (ppm), significantly higher than historical levels. A sobering fact is that 1,000 ppm of CO2 equates to a 10°C increase in global temperatures.
Taking Responsibility and Becoming Part of the Solution
Addressing climate change is - and should be - a shared responsibility that transcends borders and ideologies. To ensure a sustainable future for generations to come, individuals, governments, and corporations must take action. This includes:
1. Transforming the Energy Sector: Transitioning to renewable energy sources and reducing reliance on fossil fuels such as oil and natural gas.
2. Transportation Reform: Phasing out internal combustion engines and incentivizing sustainable transportation methods.
3. Personal Carbon Reduction: Adopting lifestyle changes like reducing meat consumption, flying less, and minimizing energy use.
Many such measures, with different levels of commitment and success have been adopted and embarked on worldwide by governments and through global agreements such as the Paris Agreement. The Paris Agreement is a legally binding international treaty on climate change. It was adopted by 196 Parties at the UN Climate Change Conference (COP21) in Paris, France, in December 2015 and became effective in 2016. Its overarching goal is to hold “the increase in the global average temperature to well below 2°C above pre-industrial levels” and pursue efforts “to limit the temperature increase to 1.5°C above pre-industrial levels.”
Since its adoption, the Paris Agreement has driven near-universal climate action by setting goals and sending signals to the world regarding the urgency of responding to the climate crisis. While action is proceeding, much more is needed now on all fronts.
Decarbonizing the Industrial Sector
The industrial sector is a significant contributor to greenhouse gas emissions, accounting for approximately 40% of emissions globally. To keep global warming to no more than 1.5°C – as called for in the Paris Agreement – emissions need to be reduced by 45% by 2030 and reach net zero by 2050. These are very lofty goals, and despite ongoing action and increasing effort, quite difficult to reach at the current pace of change.
Many governments (including the United States) have adopted net zero 2050 goals and strategies. In a nutshell, achieving a net-zero future by 2050 requires a roadmap focused on:
1. Materials and Energy Efficiency: Reducing resource consumption and enhancing energy efficiency.
2. Transitioning to Low-Carbon Fuels: Shifting from carbon-intensive fuels to cleaner alternatives.
3. Carbon Capture, Utilization, and Storage (CCUS): Developing technologies to capture and store CO2 emissions.
Additional measures have been put fourth by organizations such as Project Drawdown, a climate change mitigation project initiated by Paul Hawken and climate activist Amanda Joy Ravenhill. The main principles of the project are to:
Reduce sources by bringing emissions to zero and stopping pollution.
Support sinks and uplift nature's carbon cycle.
Improve society by fostering equality for all.
Overcoming Challenges and Building a New Economy
Addressing climate change poses many challenges, including cost, technological solutions, policy support, and the need for innovative business models such as the circular economy. However, the potential benefits of a green transition far outweigh these challenges, once one accounts for the true current cost on the planet of things like pollution, carbon emmissions, and environmental degradation.
Economic prosperity is intricately linked with the health of the natural world, and once we start to consider not just traditional sources of capital like finance and labor, but natural capital, we begin to transition to an economy that may be truly sustainable. The fundamentals of climate change are clear, and the need for action is urgent. The impact of climate change extends beyond environmental concerns; it affects our economy, well-being, and the prospects for future generations.
To leave the world better than we found it, we must collectively work toward mitigating and reducing our emissions while prioritizing the preservation of our natural world. As humanity has overcome immense challenges in the past, so too can we rise to the occasion and do the right thing now for our planet, our only home.
Sources:
“Climate Change and Sustainability Essentials” - Udemy.com course by Dr Yishay Mor and Pierre-Antoine Ullmo. https://www.udemy.com/course/climate-change-a-short-introduction/
“Technical dialogue of the first global stocktake Synthesis report by the co-facilitators on the technical dialogue” - United Nations Framework Convention for Climate Change (FCCC), September 2023
Wikipedia.org
