Author: Anggi Dewita

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Introduction

Climate change emerges as a global threat that must be addressed immediately. The phenomenon creates disturbances in ecosystem functions that threaten biodiversity, water, food security, and resource availability and becomes a security threat to humanity (Brown et al., 2007; IPCC, 2014). Based on the strong scientific consensus, the current climate-warming trends are extremely likely to be caused by anthropogenic activities since humans emit greenhouse gases (GHGs) that stay for a long time in the atmosphere (IPCC, 2014). Even though GHGs can naturally be present in the environment, climate scientists have reached an agreement with a number of studies converging on a 97% consensus that humans are the major contributors to current GHGs (Cook et al., 2017). In addition, most of the leading scientific organisations are in line with the statement (Climate NASA, 2020). Humans have emitted greenhouse gases (GHGs) such as methane and carbon to the Earth’s atmosphere since the Industrial Revolution. GHGs from human activities have been responsible for more than half of the global mean temperature increase since 1951 (IPCC, 2014).

CO2 in the atmosphere

Carbon dioxide is a visibly transparent gas. In other words, it allows sunlight to pass through. However, infrared radiation, or longwave radiation, is absorbed by CO2 and many other greenhouse gases (GHGs), which ultimately re-emit it both vertically upwards and back down to the surface. This infrared radiation essentially constitutes heat radiation emitted by the Earth’s surface. When we have a much lower concentration of GHGs, this infrared radiation penetrates through the atmosphere and escapes into space. However, as we are currently experiencing much higher concentrations, not only of carbon dioxide but also many other long-lived GHGs, including methane, nitrous oxide, and chlorofluorocarbon, their increases in the atmosphere over the last 100 years have been primarily due to human activity (Sremac & Salehi, 2018).

Impacts of Rising Earth Temperatures

Greenhouse gases that humans emit can prevent heat energy from escaping space. The heat that cannot leave the Earth’s surface is distributed globally by the Earth’s circulation and increases the surface temperature, and we call this phenomenon global warming. (Lindenmayer et al., 2010). The warming triggers concatenation phenomena that alter climate patterns. Seven variables are identified as indicators of climate change (WMO, 2021): 1. Surface Temperature 2. Atmospheric CO2 3. Sea Level 4. Ocean Acidification 5. Ocean Heat Content 6. Glacier Mass Balance 7. Sea
Ice Extent

The global surface temperature was 0.99°C higher in the first two decades of the 21st century relative to 1850-1900. The warming occurs less strongly over oceans than on land (1.59 ⁰C cooler). It also strengthens climate and weather extremes with implications for heatwaves, drought, and extreme precipitation to become more severe and frequent (IPCC, 2021). Humans get the impact directly through physical and mental health challenges and indirectly through the disturbance in ecosystem services that are critical in many facets, including agriculture, water security, built environment, and resource availability (IPCC, 2014).

Climate Tipping Point

A tipping point refers to a significant and irreversible shift that occurs abruptly once a specific threshold is crossed (McKay et al, 2022.). Climate pattern alterations typically result in changes that are perceived as gradual and linear, such as the increase in heat waves with the rise in average global temperatures. In theory, these changes can be gradually mitigated and even reversed through the reduction and removal of harmful emissions from the atmosphere. However, tipping points represent a distinct phenomenon. They can occur suddenly, akin to flipping an on-off switch, propelling climate systems into entirely new states. Moreover, they tend to be either irreversible or challenging to reverse. These alterations could result in irreversible, abrupt, and perilous consequences with serious ramifications for humanity. Climate tipping points are highly related to the environmental tipping points. Anticipated consequences associated with a warming of approximately 1.5°C encompass the sudden thawing of permafrost in boreal forests, including Canada’s, the cessation of a current in the Labrador Sea, the disintegration of ice sheets in Greenland and West Antarctica, and the decline of coral reefs at lower latitudes, such as Australia’s Great Barrier Reef (McKay et al., 2022).

Notably, even the existing 1°C global warming threshold has the potential to activate certain tipping points, posing significant risks. Under the Paris Agreement, many countries agreed to limit the temperature increase to 2°C above pre-industrial levels but set a goal of 1.5°C (United Nations, 2020).

Conclusion

Climate change is a pressing global threat caused primarily by human activity, emitting greenhouse gases that trap heat in the atmosphere. This results in ecological disturbances, posing risks to biodiversity, water, food security, and resources, and threatens global security. Rising temperatures intensify extreme weather events, affecting health and ecosystem services. Moreover, climate tipping points represent abrupt, often irreversible shifts that challenge humanity. Swift action is essential to mitigate this crisis and meet global temperature goals outlined in the Paris Agreement.