聯合國：世界在應對氣候變遷方面遠未達到目標

The United Nations has released a concerning report indicating that global efforts to combat climate change are significantly off course. The report highlights that greenhouse gases, which are responsible for rising temperatures, are accumulating at an unprecedented rate. Current national strategies aimed at reducing carbon emissions are insufficient, and if these plans remain unchanged, the world is unlikely to keep the temperature increase below 1. 5 degrees Celsius this century. This threshold is critical, as scientists warn that exceeding it could lead to catastrophic consequences for the planet. The report reveals that greenhouse gas levels have surged by over 11% in the past two decades, with concentrations reaching alarming heights in 2023. Researchers are particularly worried about the diminishing capacity of forests to absorb carbon, which may be exacerbating the already record levels of warming gases in the atmosphere. A striking example of the impact of rising temperatures is illustrated by an incident in Lisbon, where a woman collapsed due to heat exhaustion, underscoring the immediate dangers posed by extreme weather conditions. The UN has conducted an analysis of carbon reduction plans submitted by nearly 200 countries to assess progress in curbing emissions that threaten to push global temperatures well above the critical 1. 5 degrees Celsius mark. The findings indicate that, when aggregated, these plans would result in a mere 2. 6% reduction in emissions by 2030 compared to 2019 levels. This figure falls drastically short of the 43% reduction that scientists deem necessary by the end of this decade to maintain a trajectory toward net-zero carbon emissions by 2050. Simon Stiell, the executive secretary of UN Climate Change, expressed that the report's findings are alarming yet not unexpected. He emphasized that the current national climate plans are far from adequate to prevent global warming from severely impacting economies and livelihoods worldwide. The UN is urging countries to submit new, more ambitious plans by the spring of next year, and discussions on enhancing these efforts will be a central theme at the upcoming UN climate conference next month. The report also highlights the role of forest fires in contributing to the emissions trend observed in 2023. The WMO has noted that the increase in greenhouse gas concentrations last year was greater than in the previous year, driven by record-breaking fires in Canada and the onset of the El Niño weather phenomenon, alongside ongoing emissions from fossil fuels. Furthermore, WMO scientists have observed that as global temperatures rise, trees are becoming less effective at absorbing carbon dioxide. Data suggests that the southeastern Amazon has transitioned from being a carbon sink to a carbon source. Dr. Oksana Tarasova from the WMO explained that deforestation in the Amazon leads to a series of negative consequences, including increased temperatures and altered air circulation patterns. This results in reduced precipitation and diminished carbon uptake, causing more carbon dioxide to remain in the atmosphere. The Amazon serves as a prime example of what scientists refer to as climate feedback, where rising temperatures exacerbate natural systems that contribute to warming. If forests and oceans lose their ability to absorb carbon dioxide, the pace of global warming could accelerate significantly. Dr. Tarasova acknowledged that while there are clear indicators of this phenomenon, it is challenging to attribute it solely to climate feedback due to the variability introduced by weather events like El Niño and La Niña. The WMO pointed out that the last time the Earth experienced comparable levels of atmospheric carbon was 3 to 5 million years ago, a period when average temperatures were 2 to 3 degrees Celsius higher than today, and sea levels were 10 to 20 meters higher.