Set 1 | Important Greenhouse Effect and Climate Change MCQs

Correct Answer is D.

• Greenhouse gases and pollution directly contribute to ozone depletion, while the depletion of the ozone layer indirectly influences climate change.

Correct Answer is B.

• Since 1900, Earth’s average surface air temperature has risen by approximately 1 °C (1.8 °F), with more than half of this increase occurring since the mid-1970s.
• Numerous observations, including the shrinking Arctic sea ice extent, rising ocean heat content, and shifts in temperature-sensitive species such as fish, mammals, and insects towards the poles, collectively offer undeniable proof of global-scale warming.

Correct Answer is B.

• The greenhouse effect is a natural phenomenon that heats the Earth’s surface. When sunlight reaches the Earth’s atmosphere, part of it is reflected back into space, while the remainder is absorbed and re-emitted by greenhouse gases.
• These gases, including water vapor, carbon dioxide, methane, nitrous oxide, ozone, and certain human-made chemicals like chlorofluorocarbons (CFCs), trap heat.
• This trapped energy warms both the atmosphere and the Earth’s surface, a process commonly referred to as the greenhouse effect.

Correct Answer is C.

• The concept of greenhouse gases was first proposed by Joseph Fourier in 1824. Fourier suggested that Earth’s atmosphere acts like a glass cover, trapping heat and keeping the planet warm.
• This idea laid the groundwork for understanding the greenhouse effect, later refined by scientists like John Tyndall in 1859, who identified specific gases such as water vapor and carbon dioxide as key contributors to this effect.
• Svante Arrhenius further expanded on this in 1896 by quantifying the relationship between carbon dioxide levels and global temperature changes, marking a critical step in climate science.

Correct Answer is *.

• Greenhouse gases in Earth’s atmosphere act as a shield, allowing shortwave radiation from the sun to pass through but trapping longwave radiation emitted by the Earth.
• This leads to an increase in Earth’s atmospheric temperature, a phenomenon known as the greenhouse effect. While an increase in atmospheric carbon dioxide enhances the greenhouse effect, there is no conclusive evidence suggesting a significant rise in carbon dioxide concentration solely due to the greenhouse effect. Hence, option (a) is incorrect.
• Water vapor, a major greenhouse gas, plays a crucial role in the greenhouse effect and is influenced by its intensity. Higher atmospheric heat caused by the greenhouse effect accelerates evaporation, increasing air humidity. Thus, option (b) is correct.
• The greenhouse effect, by increasing heat and humidity, can positively impact the reproduction and fertility of organisms. However, while this is true, it does not qualify as an atmospheric change, disqualifying it as the correct answer.
• The greenhouse effect primarily influences temperature and pressure. Rising temperatures lead to increased atmospheric pressure and enhanced air mobility, making option (d) correct in the context of the question. Therefore, both options (b) and (d) are correct.

Correct Answer is C.

• The Kyoto Protocol is an international treaty associated with the United Nations Framework Convention on Climate Change (UNFCCC). It binds its signatory parties to adhere to internationally agreed-upon targets for reducing greenhouse gas emissions.

Correct Answer is B.

• The Kyoto Protocol was adopted in Kyoto on December 11, 1997, and came into force on February 16, 2005, making statement (1) correct.
• It is an international agreement associated with the United Nations Framework Convention on Climate Change (UNFCCC), which contradicts the claim in statement (2), rendering it incorrect.
• The global warming potential (GWP) of a gas is influenced by the efficiency of its atoms and its environmental life cycle. While carbon dioxide’s environmental life cycle can vary, its GWP remains constant at 1.
• Methane, however, has a significantly higher GWP of 72 over a 20-year timeframe, making it a more potent and dangerous greenhouse gas than carbon dioxide.

Correct Answer is D.

• Cartagena Protocol – Biosafety: Focuses on the safe handling, transfer, and use of living modified organisms (LMOs) to protect biodiversity and human health.
• Stockholm Convention – Persistent Organic Pollutants: Aims to eliminate or restrict the production and use of persistent organic pollutants (POPs) that harm the environment and health.
• Montreal Protocol – Ozone Layer Protection: Seeks to phase out substances that deplete the ozone layer, crucial for protecting life from harmful UV radiation.
• Kyoto Protocol – Climate Change: Establishes binding targets for reducing greenhouse gas emissions to combat global warming and climate change.

Correct Answer is B.

• The greenhouse effect occurs when environmental gases absorb infrared radiation. The primary greenhouse gases include carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons.

Correct Answer is C.

• In February 2018, the Government of Singapore announced the implementation of a carbon tax as part of its commitment to reducing greenhouse gas emissions under the Paris Climate Agreement.
• The tax is aimed at incentivizing companies to reduce their carbon footprints and promote cleaner energy alternatives. Singapore’s carbon tax applies to both local and foreign entities that produce or import carbon emissions, with the goal of driving innovation in green technologies and achieving a sustainable, low-carbon future.
• This initiative is part of Singapore’s broader environmental strategy to meet its climate targets, enhance energy efficiency, and contribute to global efforts in combating climate change.