May 2024 has a lot in common with April and March, as well as the nine months before it: It was the warmest month worldwide since measurements began. Global monthly mean temperatures have been consistently higher than all previous monthly means in the Copernicus dataset since June 2023. The new monthly records in the second half of 2023 were even far outside what was previously known, even compar to global temperature datasets dating back to 1850: Compar to the average of all 12 monthly records that exist before June 2023 (see purple dots in Figure 1; deviation from 1991-2020: +0.5 °C), the average from June 2023 to May 2024 was 0.25 °C higher (deviation from 1991-2020: +0.75 °C).
Over the entire year, the monthly mean values were on average almost 3 standard deviations above the 1991-2020 norm (white zero line as mean in Figure 1). The question arises: What are the reasons for this? We summarize the current state of knowlge here.
What processes could be responsible for the current warming?
It is scientifically undisput that greenhouse gas emissions from human activity are significantly changing the global climate. From around the middle of the 20th century, the influence of our emissions became clearly apparent as the main cause of the ongoing global temperature rise. The resulting warming since pre-industrial times in 2023 was +1.3 °C.
At the same time, other processes can influence short-term temperature fluctuations. These include natural drivers such as volcanic eruptions, aerosols or solar activity. Finally, there are also natural climate fluctuations that can lead to exceptionally warm – but also cooler – years in irregular waves. In the period 1850-2020, this so-call israel mobile database natural variability contribut little or nothing to global warming (range: -0.23 °C to +0.23 °C).
The exact way these processes work in relation to global warming is explain in more detail at the end of this blog for those interest.
How can these processes explain the striking warming observ over the last 12 months?
Researchers are currently intensively studying the why should you consider email marketing when creating strikingly warm period. No clear conclusions can therefore be provid in this blog. Figure 2 graphically illustrates the scientific results publish to date. It can therefore be stat that the sum of all natural processes and man-made emissions can actually agent email list partly explain the additional global warming of 0.25 °C (averag from June 2023 to May 2024). In addition to the strong global warming caus by greenhouse gases, a volcanic eruption, the El Niño phenomenon and the desulfurization of ship fuels were add as additional factors.
However, simply adding up all the numbers is too simplistic, as the processes mostly interact with each other. The ongoing research projects in the coming years will have to show whether the previous results can be finally confirm.