Human Activities and Carbon Emissions

Each year, human activities release more carbon dioxide into the atmosphere than natural processes can remove, leading to an increase in atmospheric carbon dioxide levels.

Record High in 2023

The global average carbon dioxide concentration reached a new record high of 419.3 parts per million in 2023.

Increase Since Pre-Industrial Era

Atmospheric carbon dioxide levels are now 50 percent higher than they were before the Industrial Revolution.

Rate of Increase

The annual rate of increase in atmospheric carbon dioxide over the past 60 years is about 100 times faster than previous natural increases, such as those that occurred at the end of the last ice age (11,000-17,000 years ago).

Impact on Ocean pH

The ocean has absorbed enough carbon dioxide to lower its pH by 0.1 units, resulting in a 30% increase in acidity.

Carbon dioxide in the atmosphere warms the planet, causing climate change. Human activities have raised the atmosphere’s carbon dioxide content by 50% in less than 200 years. Carbon dioxide (CO₂) is an important heat-trapping gas, also known as a greenhouse gas, that comes from the extraction and burning of fossil fuels (such as coal, oil, and natural gas), from wildfires, and natural processes like volcanic eruptions.

India's Contribution to Global Emissions

Rising Emissions

●India’s CO2 emissions are expected to grow by 4.6% in 2024, the highest among major economies.

●This includes increases from coal (4.5%), oil (3.6%), natural gas (11.8%), and cement production (4%).

Global Standing

●India contributes 8% of global fossil CO2 emissions, ranking third after China (31%) and the U.S. (13%). The European Union (EU-27) contributes 7%.

Per Capita Emissions

●India’s per capita CO2 emissions are 0.6 tonnes, significantly lower than the global average of 1.3 tonnes, the U.S. at 3.9 tonnes, China at 2.3 tonnes, and the EU-27 at 1.5 tonnes.

Global Trends in Emissions

●Emissions from coal, oil, and natural gas are expected to rise by 0.2%, 0.9%, and 2.4%, respectively, in 2024.

●CO2 concentrations in the atmosphere are projected to reach 422.5 ppm in 2024, which is 52% higher than pre-industrial levels.

Carbon Budget and the 1.5°C Threshold

●The remaining global carbon budget is depleting, with a consistent breach of the 1.5°C target expected within six years if current trends persist.

●The mean global temperature already surpassed 1.5°C in January 2024 when averaged over the previous 12 months.

Land and Ocean Carbon Sinks

●Land and oceans absorbed about half of human-generated CO2 emissions in the past decade.

●Oceans absorbed 10.5 billion tonnes annually, or 26% of total emissions, despite a 5.9% decline in absorption efficiency over the last decade due to altered wind patterns and warming waters.

●El Niño temporarily reduced land CO2 absorption in 2023 but is expected to recover by mid-2024.

Role of Carbon Dioxide

Carbon dioxide (CO2) is Earth's most important greenhouse gas, absorbing and radiating heat.

Unlike oxygen and nitrogen, it traps heat from Earth's surface and re-emits it, warming the planet.

Without CO2, Earth's natural greenhouse effect would be too weak to maintain temperatures above freezing.

Impact on Global Warming

Human activities are increasing CO2 levels, enhancing the greenhouse effect and raising global temperatures.

In 2021, CO2 accounted for about two-thirds of the total heating effect from human-produced greenhouse gases, as observed by NOAA.

Ocean Acidification

CO2 dissolves in the ocean, forming carbonic acid and lowering its pH.

Since the Industrial Revolution, the ocean's surface pH has dropped from 8.21 to 8.10, increasing acidity—a process known as ocean acidification.

CO2 Emissions in the Building Sector

Significant CO2 outflows due to non-sustainable energy sources used in planning, construction, and operations of buildings.

Urbanization also contributes to emissions.

Fossil Fuel Dependence

Fossil fuels account for 94% of energy use in the building sector, with only 6% coming from renewable sources.

Construction activities contribute to 40% of global greenhouse gas emissions.

Direct vs. Indirect CO2 Emissions

85% of global CO2 emissions from buildings are indirect (from electricity use), while 14% are direct (from burning natural gas, diesel, etc.).

Challenges in Reducing Emissions

Current methods to reduce the CO2 footprint in high-density urban areas have limited success.

Non-sustainable energy use directly impacts the environment.

2030 Climate and Energy Framework

Targets 27% of energy from sustainable sources and a 27% increase in energy efficiency.

However, challenges persist in improving productivity and efficiency.

Solutions for Sustainability

Detailed evaluation of construction and operational processes, including material assembly, structure development, machinery operation, and maintenance.

Life cycle assessment can identify areas for efficiency improvements.

Global Efforts on CO2 Reduction

Over the past two decades, governments have been urged to mitigate CO2 emissions across sectors, especially in the building sector.

Sustainable Building Strategies

Various strategies at different scales are applied to reduce CO2 emissions in buildings, including sustainable standards, codes, policies, and guidelines aimed at improving energy performance.

Paris Agreement & NDC

Under the Paris Agreement and UN Sustainable Development Goals, the Nationally Determined Contribution (NDC) was established in 2015 for building sector decarbonization.

A total of 184 countries are participating in NDC commitments.

Country Initiatives

Governments have introduced policies and standards to decarbonize buildings, focusing on energy performance and efficiency.

More than 60 countries have plans to implement these standards either mandatorily or voluntarily.

Goal

The aim is to achieve zero or low-carbon buildings by setting minimum energy performance requirements.

 PRACTICE QUESTION

Q.The rise in carbon dioxide (CO2) levels in the atmosphere is one of the most significant contributors to global warming and climate change. Discuss the main causes behind the increasing CO2 levels and their impact on the environment and human health. (250 words)