Global Affairs

Step 1: Understanding the Paris Climate Agreement.
The Paris Climate Agreement is an international treaty aimed at limiting global warming to below 2°C above pre-industrial levels, with efforts to limit it to 1.5°C. It was adopted in 2015 and entered into force in 2016. The agreement was signed by almost every country at the COP21 conference in Paris.

Step 2: Analyzing the options.
(A) 2016: This is when the Paris Climate Agreement officially entered into force, but the signing took place in 2015.
(B) 2015: Correct — The Paris Climate Agreement was signed in 2015 at the COP21 conference.
(C) 2003: This is incorrect, as the Paris Agreement was signed long after 2003.
(D) 1997: This refers to the Kyoto Protocol, not the Paris Climate Agreement.

Step 3: Conclusion.
The correct answer is (B) 2015, as the Paris Climate Agreement was signed at the COP21 conference in Paris in that year.

Step 1: Understanding greenhouse gases.
Greenhouse gases are gases that trap heat in the Earth's atmosphere, contributing to the greenhouse effect. Common greenhouse gases include carbon dioxide (CO₂), methane (CH₄), water vapour (H₂O), and ozone (O₃).

Step 2: Analyzing the options.
(A) Water vapour: Water vapour is a greenhouse gas.
(B) Carbon-dioxide: Carbon-dioxide is a major greenhouse gas.
(C) Hydrogen: Correct — Hydrogen is not considered a greenhouse gas.
(D) Ozone: Ozone is a greenhouse gas that exists in the Earth's atmosphere.

Step 3: Conclusion.
The correct answer is (C) Hydrogen, as it is not a greenhouse gas.