INCREASE IN GLOBAL MEAN SURFACE TEMPERATURE

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TAG: GS 3: ECOLOGY AND ENVIRONMENT

THE CONTEXT: A recent study forecasts unprecedented global mean surface temperatures during the 2023-2024 winter, potentially breaking historical records due to the confluence of the El Nino event and an enduring global warming trend.

EXPLANATION:

• The paper, published in Advances in Atmospheric Sciences, highlights projections that could push temperatures beyond the critical 1.5-degree Celsius threshold above pre-industrial levels, with far-reaching implications for the environment.

TEMPERATURE TRENDS AND PROJECTIONS:

• Temperature Anomalies:
  • The global average temperature from June to October 2023 surpassed the 1991-2020 average by 0.57℃.
  • In August and September, temperatures surpassed historical averages by 0.62℃ and 0.69℃, respectively, beating the 2016 record.
• Global Projection:
  • It projects a potential 1.38°C rise in global mean surface temperatures in 2023, possibly surpassing the 2016 record of 1.29°C above pre-industrial levels.

DRIVERS OF TEMPERATURE INCREASE:

• El Nino Impact:
  • The emergent El Nino pattern, coupled with the persistent long-term warming trend, is identified as the primary drivers of the escalating temperatures.
• Consequences:
  • The forecasted temperature rise could exacerbate sea-level rise, sea-ice loss, and significantly impact the global ecosystem and food security, with potential ramifications extending into 2024.

TEMPERATURE EXCEEDANCE AND REGIONAL IMPACTS:

• Temperature Records:
  • In 2023, temperatures surpassed 1.5°C above pre-industrial levels on 86 days, leading to heatwaves impacting North America, southern Europe, and Asia during summer.
• Regional Projections:
  • Multiple climate prediction systems indicate exceptionally warm winter conditions in mid-low latitude regions of Eurasia and the Americas, especially in China, expected to experience abnormal warming significantly surpassing the global average.

EL NINO’S ROLE AND PREDICTIONS:

• Mature El Nino:
  • Anticipated maturation of El Nino this winter, releasing heat into the atmosphere and potentially enhancing global mean surface temperatures.
• Impending Climate Variations:
  • El Nino’s dominance in the 2023-2024 northern hemisphere winter is expected, triggering anomalous anticyclone activity in the Northwest Pacific, leading to warm and dry weather patterns.

IMPACT ON PACIFIC-NORTH AMERICAN ATMOSPHERIC TELECONNECTION:

• Teleconnection Patterns:
  • El Nino may initiate a Pacific-North American atmospheric teleconnection, influencing winter climates in East Asia and North America.
• Typical Outcomes:
  • Positive phases of this pattern could result in above-average temperatures in western Canada and western U.S., contrasting with below-average temperatures in south-central and southeastern U.S., linked to reduced precipitation in specific regions.

CONCLUSION:

• The study underscores the potential for unprecedented winter temperatures in 2023-2024, propelled by El Nino’s intensification and the continued global warming trend.
• These projections have far-reaching implications for regional climates, ecosystems, and food security, necessitating preparedness and mitigation strategies to address the anticipated environmental impacts.

SOURCE: https://www.downtoearth.org.in/news/climate-change/study-warns-of-new-warming-records-this-winter-driven-by-el-nino-long-term-global-warming-trend-93095