Global warming due to carbon dioxide-based radiative forcing did not resist to a critical analysis largely based on fundamentals of chemistry, physics and thermodynamics. This finding led to giving water an essential role in an alternative mechanism in which heat and not CO2 is climate determinant. This mechanism is based on ice ↔ liquid water and liquid water ↔ vapor interphase equilibria combined with the physics of infrared waves when they pass through the atmosphere. Accordingly, future global average temperature and ocean level rises should be smaller than predicted in the case of radiative forcing. Climatic events depending on chaotic perturbations, increases in strength and frequency are expected if anthropogenic heat releases become significant relative to solar heat supplies. Applied to distant past climate fluctuations, the water-based heat-management mechanism showed that ice melting, evaporation and humidity also determined the ups and downs of temperature and ocean level during glaciation-deglaciation alternating periods. The present times are part of the last post-deglaciation pseudo plateau in which variations of global temperature are limited to ± 2°C, a range respected during the last 8,000 years, including the recent industrial era, and comparable to plateau periods in distant past. It is in this plateau period that anthropogenic heat releases are presently complementing historical heat supplies from the Sun. Heat being a physical phenomenon independent of the sources, global temperature and level of oceans should continue to vary within the rather narrow ranges typical of past plateau periods provided anthropogenic heat releases remain negligible relative to solar supplies. If it is not the case, ice melting and evaporation may become unable to compensate anthropogenic heat supplies. The + 2°C limit would then be exceeded with progressively more evaporation, more winds, more hurricanes, more tornadoes, more clouds, more rains, more floodings and droughts, and at the end shortening of the time to next glaciation. Trend may seem already manifest on the basis of local recent climatic events felt unusual. However, the stock of ices is such that the evolution should extend over several centuries, may be more if evaporation acts in complement.
Unlike the radiative forcing linked to CO2 and its cumulative storage in oceans since the start of the industrial era around two centuries ago, the Sun has heated the Earth for billions of years without accumulation and dramatic temperature drift. To overcome this obviously illogical difference in evolution, we first analyze several reasons showing that the current universally adopted relationship between carbon dioxide and global warming does not respect the fundamentals of Chemistry, Physics, and Thermodynamics. A recently proposed alternative mechanism, based on these hard sciences, is briefly recalled. In this new mechanism, heat on Earth is managed by water and its solid-liquid and liquid-vapor interphases equilibria before radiative elimination in space. Today, anthropogenic heat is increasingly seen as a complement to the solar heating although it is neglected in the universally adopted consensus. Anthropogenic heat releases are generally estimated from global energy consumption. A broader list of sources is established that includes the capture of solar thermal infrared radiations by artificial installations, including those acting as greenhouses. Three qualitative scenarios are proposed in which climate change depends on whether the ratio of anthropogenic heat releases relative to solar thermal contributions remains negligible, is acceptable or becomes so large that it could shorten the time until the next ice age. Currently, global temperature and ocean level are still very low compared to those in distant past. On the other hand, ice disappearance is indisputable, particularly at the levels of glaciers, floating ice, and permafrost. These features fit the scenario in which temperature continued to fluctuate as it did during the last 8,000 years of the current Holocene interglacial plateau while local rains, winds, floodings, droughts, etc., worsen in magnitude and frequency to help ice melt and evaporation manage excess heat. Policymakers should not wait to discover that decreasing atmospheric carbon dioxide has little effect on the worsening of climate events to begin mitigating of anthropogenic heat with the help of hard sciences scientists to work on quantification. Key points • Carbon dioxide-based radiative forcing as source of global warming does not resist to critical analysis based on fundamentals of chemistry, physics and thermodynamics • Thermal properties of water, water interphase exchanges, formation of clouds and radiative elimination to space control heat supplies and climate changes since water is present on Earth • Anthropogenic heat releases should not affect much temperature and ocean levels provided they remain negligible relative to solar heat supplies, but heat-dispersing local climatic vents should increase in strength and frequency