Environmental Science

The theme for World Water Day 2024 was 'Water for Peace'. The other options represent themes from different years: 'Groundwater: Making the Invisible Visible' (2022), 'Accelerating Change' (2023), and 'Water and Gender' (2006).

The largest source of pollution globally is industrial effluents and emissions, primarily from the burning of fossil fuels in industries and power plants. According to recent data, the energy and industrial sectors contribute the majority of global greenhouse gas emissions and pollution. While automobile exhausts are a significant source of air pollution, industrial activities including power generation, manufacturing, and chemical production contribute a larger share overall. Herbicides, insecticides, sewage, and garbage also contribute to pollution but on a smaller scale compared to industrial emissions.

Argo is an ocean monitoring system primarily designed to measure ocean temperature and salinity profiles using a global array of autonomous floats. It does not measure ocean pH, so option A is correct.

The term 'second ozone hole' is not a standard scientific term. The major and most significant ozone hole is the one over Antarctica, which has been observed annually since the 1980s. In 2006, the Antarctic ozone hole was notably large, the largest ever observed at that time. There was also an unusually large ozone depletion event over the Arctic in 2006, but it was not commonly referred to as a 'second ozone hole.' The question likely refers to the Antarctic ozone hole, which is the primary and most significant ozone depletion area. The other options (Brazil, China, Tibet) are not known locations for ozone holes. Therefore, the correct answer remains Antarctica.

The first biogas plant was established in 1911, making option B correct. This is a well-documented historical fact in renewable energy development.

Chlorofluorocarbons (CFCs) are the primary substances responsible for the depletion of the ozone layer in the Earth's stratosphere. They release chlorine atoms upon breakdown by UV radiation, which catalyze the destruction of ozone molecules.

The Greenhouse Effect is primarily caused by an excess of greenhouse gases like carbon dioxide in the atmosphere, which trap heat and lead to global warming. Carbon monoxide and carbon tetrachloride do not significantly contribute to this effect.

The Earth's ozone layer primarily functions to filter out harmful ultraviolet (UV) rays from the sun, protecting living organisms from UV radiation damage. It does not prevent global warming or absorb pollution directly.

Carbon dioxide makes up approximately 0.039% (or about 400 ppm) of the Earth's atmosphere by volume, which is correctly represented by option A. The other options are significantly higher and incorrect.

Acid rain is primarily caused by the emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) into the atmosphere. These gases react with water vapor to form sulfuric and nitric acids, leading to acid rain.