Thanks to numerous Earth-orbiting satellites deployed world-wide, scientists have been able to collect significant amount of data about Earth’s climate on a global scale. Extensive studies produced indisputable information, thus detailed records collected over decades demonstrated that the Earth’s average surface temperature has risen faster in the last few decades than it did in the previous ~2000 years. To be more specific, the planet's average temperature has risen approximately 0.9 degrees Celsius (equally 1.62 degrees Fahrenheit) since the XIX century.
A significant amount of the excess heat is absorbed by the ocean. Nearly one kilometer of ocean surface warmed up to more than 0.22 degrees C since 1969. The excess heat drives the seasonal temperatures to extremes and consequences are obvious. The physical implications of global warming have already been systematically identified. Extreme weather events, intensified rainfall, changes in the timing of seasonal events, sea-level rise, reduction of Arctic sea ice and glacier retreat are all day-to-day issues, resulting in habitat changing for plants and animals.
A dominant driver of global warming is a greenhouse effect, produced by greenhouse gases (GHG). The primary greenhouse gases are water vapor, carbon dioxide, methane, nitrous oxide, and ozone, because of their ability to absorb and emit energy within the infrared spectrum.
According to the Renewable Energy Roadmaps analysis, the share of renewables in power generation would need to increase from around one-quarter in 2015 to around 60% by 2030 and 85% by 2050 for energy sector decarbonisation.”
Since the recognition of the problem, numerous objectives were specified worldwide in order to strengthen the global response to climate change, with the final aim of keeping the global temperature rise below 2 degrees Celsius above the pre-industrial levels. Three global legal instruments enforcing the climate-conscious actions, the United Nations Framework Convention on Climate Change (UNFCCC), Kyoto Protocol, and Paris Agreement, are established in 1992, 1997, and 2015, respectively. They are designed to (1) establish a framework of general principles by which the level of greenhouse gas concentrations in the atmosphere should be stabilized - UNFCCC; (2) commit industrialized countries to take actions in accordance with agreed individual targets - Kyoto Protoco; bind all parties, including countries in development, to establish, implement, respect, and regularly report on the nationally determined contributions - Paris Agreement.
European Union actively participated in all three protocols and set up a roadmap for 2030 target consisting of (1) minimum 40% cut in GHG emissions with respect to 1990 levels; (2) minimum of 27% share of renewable energy in total energy consumption; (3) 27% minimum improvements in energy efficiency across the EU territory. The 2030 steps are intended to lead towards long-term EU goal set for 2050: cutting the GHG emissions by 80-95% below the 1990 level and becoming the world’s first climate-neutral continent by 2050. To realize this goal European Commission presented a set of guidelines and measures in the form of the European Green Deal, in December 2019.
The U.S. Climate Alliance is "a bipartisan coalition of governors committed to reducing greenhouse gas emissions consistent with the goals of the Paris Agreement". They announced to achieve GHG emissions reduction of 26% - 28% in 2025 compared with its 2005 level. In the US, the main source of carbon dioxide emissions, about 40%, is oil, which is followed by natural gas (28.6%).
The world’s largest emitter of greenhouse gases, China, is responsible for 28.3% of global carbon dioxide emissions in 2017. To deal with their domestic problems, affecting the global state of affairs, China initiated the process of carbon footprint reduction to 60% - 65% below 2005 levels and the increase of the non-fossil fuel share of energy supply to 20% by 2030. Approximately 73% of China’s carbon dioxide emissions result from heavy dependence on coal. This percentage of emissions is larger than those from all European, African, and Latin American countries combined. The primary coal consumer in China is its industrial sector. Manufacturing, agriculture, mining, and construction collectively made up 68% of China’s energy use and 50% of China’s coal use in 2015.
In the article, recently published by National Geographic, written in coordination with Climate Action Tracker, a list of countries doing the most and the least to reach the self-set goals is presented. The Climate Action Tracker is an independent scientific analytics team that tracks countries active in climate action to evaluate their progress. Also, on the webpage of the monitoring tool, the Climate Change Performance Index aggregated results of most country's performance are depicted within the interactive world map.
Apparently, for most countries goals were too ambitious, thus in 2017 global carbon emissions increased by 1.7% and 2.7% in 2018. Nationally determined contributions are either not sufficient or exerted lightly. To achieve a net-zero carbon before breaking the limit, redefinition of the overall industry and infrastructure at global scales are required.