What Are the Effects of Breaching the 15-Degree Celsius Global Warming Limit?

In an unprecedented climatic development, the European Union’s Copernicus Climate Change Service (C3S) has reported that the interval from February 2023 to January 2024 set a new benchmark as the warmest 12-month span on record.

Throughout this time interval, the global mean temperature surged, surpassing the pre-industrial average — established between 1850 and 1900 — by 1.52 degrees Celsius for the first time.

Previously, the Copernicus agency had declared 2023 the warmest year in over 173 years, with temperatures exceeding historical averages by 1.48 degrees Celsius.

The inclusion of data from the past January has pushed this warming average to a new mark.

Failed Paris Accord

This epoch is notably the first instance where the global mean temperature has escalated beyond the 1.5 degrees Celsius mark, offering a forewarning of a potential future where efforts to mitigate climate change falter.

The significance of the 1.5 °C threshold originates from the 2015 Paris Climate Accord, wherein virtually all nations committed to curbing greenhouse gas emissions.

The goal is to cap the global temperature rise at 2 degrees Celsius, with an aspirational target of 1.5 degrees by century’s end, harking back to pre-industrial levels.

Surpassing the 1.5 degrees Celsius average in a single year does not equate to a failure of the Paris Agreement’s objectives.

However, it signals the potential derailment of global endeavors to reach this critical target — a concern echoed in a United Nations report warning that current trajectories are misaligned with the long-term aspirations of the accord.

To avert a climate emergency, immediate and comprehensive action is imperative.

Despite growing skepticism over the feasibility of the Paris Agreement’s targets, scientists persist in urging swifter governmental action to curtail carbon dioxide emissions and prevent breaching these limits.

Climate Change

The root of global warming lies in the ongoing climate change and the resultant rise in Earth’s temperature.

This warming is attributed to the greenhouse effect, where solar heat reflected by oceans and land is trapped within the atmosphere, impeding its escape into space.

While this effect is essential for sustaining Earth’s habitable climate, human-induced spikes in greenhouse gasses like carbon dioxide, methane, and nitrous oxide have intensified this natural insulation.

The result is an amplified average global temperature and altered climate patterns over the long term.

Since the dawn of the Industrial Revolution in the 18th century, human activities have significantly increased atmospheric greenhouse gasses through the combustion of fossil fuels in transportation, manufacturing, and energy sectors, as well as deforestation.

These gasses linger in the atmosphere for extended periods, eventually being neutralized by chemical reactions or absorbed by oceans and vegetation.

However, human activities have accelerated the rate at which these gasses are emitted, outpacing their removal and leading to rising concentrations.

The enduring presence of CO2 in the atmosphere portends continued temperature increases for years ahead.

Data reveals a stark rise in carbon dioxide levels since the industrial era’s inception, climbing from a late 18th-century annual mean of 280 parts per million to 414 parts per million in 2021 — a 48% surge, predominantly due to human actions.

Methane concentrations have also doubled since pre-industrial times, now exceeding 1,800 parts per billion, primarily driven by agricultural practices and fossil fuel usage.

Climate change is further influenced by natural phenomena such as the El Niño Southern Oscillation (ENSO), which involves periodic shifts in wind and water temperatures in the eastern tropical Pacific, impacting global weather patterns.

The El Niño phase, characterized by elevated sea surface temperatures in the central and eastern tropical Pacific, was prevalent in 2023, contributing to the year’s temperature rise.

The most conspicuous manifestation of climate change is the escalation of extreme weather events, which in 2023 wrought widespread destruction through severe floods, hurricanes, and unprecedented sea surface temperatures.

These oceanic temperatures are pivotal in shaping weather events, energizing tropical cyclones, and fostering conditions conducive to heavy rainfall.

Profound Effects

The litany of extreme climate occurrences in 2023 has had profound effects on human health, ecosystems, and infrastructure, with floods, wildfires, droughts, and heatwaves marking some of the most extraordinary incidents.

Flood impacts ranged from sudden flash floods to expansive inundations, monsoonal deluges, vast low-pressure systems, and tropical cyclones.

In regions like the Horn of Africa, severe droughts have intensified flooding, reducing soil moisture and permeability, thereby hastening the runoff of rainwater into raging torrents.

Concurrently, heatwaves have swept across the globe, with arid conditions fueling extensive wildfires in locales such as Southern Europe, Canada, South America, Australia, Hawaii, and beyond.

Antarctic sea ice has receded to unprecedented levels since satellite observations began in 1979, with last year’s peak coverage in September shrinking to 16.96 million square kilometers — a full million square kilometers below the previous record low set in 1986, the World Meteorological Organization reports.

Arctic sea ice also recorded its fifth-lowest maximum extent and sixth-lowest minimum extent in history.

In a stark indicator of climate change, glaciers across western North America and the European Alps have endured intense melt-off.

Swiss glaciers, for instance, have seen a staggering 10% reduction in volume over the last two years, data from the United Nations reveals.

The repercussions of a warming planet extend far beyond melting ice, particularly in developing nations where agriculture forms the economic backbone.

Rising temperatures are desiccating farmlands, accelerating desertification, decimating crops, and fostering the emergence of novel agricultural pests.

This cascade of climatic shifts is spawning new insect, bacterial, and viral species that ravage crops, undermining national food security and exacerbating hunger and poverty.

As rural inhabitants migrate to urban centers in search of employment, cities — already grappling with scarce water resources — are further burdened.

The proliferation of slums and underserved neighborhoods, devoid of adequate healthcare and education, is a direct consequence of this demographic shift.

Moreover, extreme weather events like floods and wildfires are displacing thousands, stripping them of homes and livelihoods.

This surge in internal and cross-border migration burdens host communities, which are themselves struggling with the fallout of climate change.