Carbon Pricing Explained: Carbon Tax vs. Cap-and-Trade Systems

Greenhouse gases trap heat in Earth's atmosphere, causing global warming. The four main types are CO2 (76% of emissions), Methane (16%), Nitrous Oxide (6%), and Fluorinated Gases (4%), with warming potentials of 1, 25, 300, and 13,000 respectively. The Paris Agreement (2015) aims to limit warming to 2°C above pre-industrial levels and achieve net-zero emissions by 2050. Global CO2 emissions are led by China (15 gigatons), followed by the US (7 gigatons) and UK (5 gigatons), with per capita emissions highest in the US (22 tons). Reduction strategies include preventing emissions through renewable energy and public transportation, and absorbing emissions through forest conservation. Since the Industrial Revolution, temperatures have risen 0.7-1.0°C, with current CO2 at 450 ppm (60% above natural 280 ppm baseline). Methane emissions from livestock can be reduced through dietary changes. Proper disposal of refrigerators prevents F-gas leakage. Even small additional temperature increases could cause significant discomfort, making mitigation urgent.

The atmosphere functions like a bathtub where we add (sources) and remove (sinks) greenhouse gases. Major sources include electricity generation, food production, industry, transportation, and buildings. Nature removes about 40% of emissions through land-based sinks (primarily forests) and ocean sinks (absorbing CO2 through solubility, carbonate pump, and biological pump). Only about 60% of emissions remain in the atmosphere, building up year over year. Five sectors account for approximately 90% of global climate change: electricity generation (about 25%), food and agriculture (about 25%), industry, transportation, and buildings. This framework helps prioritize where climate action should focus.

This comprehensive section covers the foundational concepts of greenhouse gas emissions and climate change. It explains the natural greenhouse effect where atmospheric gases trap heat to maintain Earth's habitable temperature, and how human activities have thickened this layer causing global warming. The section distinguishes between global warming (temperature increase) and climate change (broader long-term climate pattern alterations). It details the six major greenhouse gases identified by IPCC: CO2, CH4, N2O, HFCs, PFCs, and SF6, each with different global warming potential values. The section covers various emission sources including stationary sources (industrial facilities), mobile sources (transportation), process emissions, forestry and agriculture, solid waste, and fugitive emissions. It covers international commitments including the Paris Agreement (2015) and Indonesia's NDC targets (29% domestic reduction, 41% with international support by 2030, net zero by 2060). The section explains the five fundamental principles guiding effective GHG inventory: Relevance, Completeness, Consistency, Transparency, and Accuracy. It details organizational boundaries (Equity Share vs Control Approach) and operational boundaries with the three-scope classification system: Scope 1 (direct emissions), Scope 2 (indirect emissions from purchased electricity), and Scope 3 (other indirect emissions from the value chain).

Since the industrial era, human activity has shifted global climate by 1-1.3°C above ancestral levels, with localized temperatures rising more dramatically and increasing extreme weather events. The Paris Climate Accord (2016) established international targets to limit warming to 2°C. Climate change is driven by cumulative greenhouse gas emissions, not annual emissions, with CO2 effects lasting hundreds to thousands of years. Over 80% of CO2 emissions come from fossil fuel combustion, with half from electricity generation. Future projections show that stabilizing temperatures at or below 2°C requires immediate and significant emission reductions, with median projections showing decreases after 2020, net zero by mid-century, and negative emissions in the latter half of the century.

Greenhouse gases (GHGs) are essential for maintaining Earth's temperature but become harmful when their concentration increases excessively, causing global warming. The seven major GHGs regulated under international agreements are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and four fluorinated gases (F-gases). Each gas has a different Global Warming Potential (GWP) value: CO2=1, CH4=28, N2O=265, and F-gases range from 1,000 to 23,000. Effective climate change mitigation requires two complementary approaches: mitigation (reducing emissions through renewable energy, energy efficiency, and sustainable practices) and adaptation (adjusting to climate impacts). Thailand has committed to achieving carbon neutrality by 2050 and net-zero greenhouse gas emissions by 2065, with a target of 40% emission reduction by 2030.

Prices function as signals that influence both consumer and producer behavior simultaneously. For consumers, rising prices reduce quantity demanded, acting as a rationing mechanism that limits purchases. For producers, rising prices incentivize increased production because higher revenues promise greater profits. This dual signaling creates a dynamic system where price changes simultaneously adjust demand and supply, creating continuous market equilibrium adjustments.

Producers receive clear signals about market conditions through observable market phenomena. When demand exceeds supply (excess demand), producers observe queuing, waiting lists, and buyer competition, signaling that prices are too low. When supply exceeds demand (excess supply), producers observe unsold inventory and excess stock in warehouses, signaling that prices are too high. These signals trigger corresponding incentives: producers want to increase prices when facing excess demand to capture additional profit, and decrease prices when facing excess supply to liquidate inventory and generate revenue.

Supply and demand are fundamental economic principles where supply represents the quantity of goods producers are willing to sell at various prices, and demand represents the quantity consumers are willing to buy; the law of supply indicates that higher prices incentivize greater production while lower prices reduce it, while the law of demand shows that higher prices decrease consumer purchases and lower prices increase them; these two forces intersect at the equilibrium price where quantity supplied equals quantity demanded, and external factors can shift these curves left or right, with elasticity measuring how responsive quantity changes are to price movements.

When demand increases for a good (causing an outward shift in the demand curve), prices rise. This price increase sends a signal to suppliers to produce more of that good. Since producers aim to maximize profits, higher prices provide an incentive to allocate more resources toward producing goods where demand is highest.

A market is a place where buyers and sellers meet to conduct transactions, with prices determined through demand and supply interaction. Consumers maximize utility within budget constraints, while producers maximize profits. The Law of Demand states an inverse relationship between price and quantity demanded: higher prices reduce demand, lower prices increase it. The Law of Supply states a direct relationship between price and quantity supplied: higher prices increase supply, lower prices reduce it. Price serves as the mechanism that regulates demand and supply, performing resource allocation functions. The demand curve plots price on the vertical axis and quantity on the horizontal axis, sloping downward to reflect the inverse price-quantity relationship. The supply curve similarly plots price on the vertical axis and quantity on the horizontal axis, sloping upward to reflect the direct price-quantity relationship.

Governments intervene in markets through taxation, subsidies, and regulations. Taxes increase prices and reduce demand, with incidence depending on relative elasticities of supply and demand. Subsidies lower production costs and increase supply, supporting domestic industries but potentially distorting market signals. The instructor explains that these interventions aim to correct market failures, redistribute income, or achieve social objectives. However, they can also create inefficiencies and unintended consequences.

In market economies, government intervention occurs through four main mechanisms: (1) Taxation (வரிவிதித்தல்), (2) Subsidies to producers (உற்பத்தி மானியம் வழங்குதல்), (3) Price controls (கட்டுப்பாட்டு விலைகளை தீர்மானித்தல்), and (4) Price supports (விலை உறுதிகளை ஏற்படுத்துதல்). These interventions are implemented when market equilibrium prices cause problems for consumers or producers.

Government intervenes in markets to address externalities through subsidies (for positive externalities) and taxes (for negative externalities). Taxes are compulsory payments with no direct benefit, classified as direct (impact and incidence on same person, no shifting) or indirect (impact and incidence on different persons, with shifting). Subsidies are government benefits to consumers or producers, functioning as anti-taxes. These interventions correct market failures by aligning private incentives with social welfare.

Governments intervene in markets to address market failures by using taxes and subsidies. This intervention is more general than monopoly-specific solutions and applies to both perfectly competitive markets and monopolies. The goal is to understand how different tax types affect production quantities, cost functions, and market outcomes.

The three main ways government can intervene in a free market economy to influence private producers and consumers are: (1) Regulations, which include minimum price and maximum price policies; (2) Financial interventions, which include taxes, subsidies, and transfer payments; and (3) Direct provision, which includes nationalization (increasing government role) and privatization (reducing government role).