Philosophy of Climate Science Part I: Observing Climate Change

Making Scientific Discoveries, 2022

Within the scientific community, there is a wide consensus that in our days there is an anthropogenic climate change. Also, there is a consensus that decades ago there was no process of this kind. Consequently, at some point in time somebody must have discovered this specific climate change, and the community must have accepted this finding as a discovery. In this paper, I will discuss the discovery of the anthropogenic climate change from a philosophy of science perspective. I will argue, that it is on the one hand a very special kind of a scientific discovery, but on the other hand, as I will show, this process of discovery illuminates on other kinds of scientific discoveries in theory, experimental and other empirical settings, and computer simulations.

2006

Since 1970 the Earth has been warming from effects of human activities. Claims to the contrary are not credible. Atmospheric composition is changing and carbon dioxide is one third higher than preindustrial levels. Global surface temperatures today are 0.75ºC warmer than at the beginning of the 20 th Century and over 0.5ºC above values in the mid-1970s, as land has warmed at double the sea surface rate. Ten of the last 11 years are the warmest on record. Global ocean temperatures are rising and ocean expansion accounts for over half the rise in global sea level of 37 mm in the past 13 years. Melting glaciers and land ice account for about 1.2 mm/year of sea level rise, and snow cover and Arctic sea ice extent are decreasing. Water vapour has risen about 4% over the oceans since the 1970s and is a key reason for widespread observed increases in intensity of precipitation and risk of floods. Hurricanes are more intense and lasting longer, and droughts have increased in intensity and extent, especially in the subtropics. All these vital signs are consistent with a warming climate. Climate models have improved and enable attribution of past change unequivocally to increased greenhouse gases, and warming is guaranteed to occur in the future from this source.

Energy Central, 2022

I have been following the developments on this critical global issue ever since my first paper on Global Warming at the Hamburg International Conference in early 1990s. Although a few thoughts have been penned here and there, its complexity seems to be getting more challenging as we progress year after year. It is also not easy for any single expert to throw up concrete steps to tackle the issue and therefore, it has to be a team work of many experts pooling their perceptions to seek ultimate solution. When we look at what is happening currently, it seems to me that we may have to draw inputs from chemical, physical, geological and biological processes that have successfully governed the climate of the past as we know and the disturbance we humans, have caused to this balanced environment. The cycles of chemical elements like carbon and nitrogen and gaseous emissions that are emitted into the atmosphere seem to be the central point of focus in order to gain an insight into this complex phenomenon.

Observing changes in the climate system : The recent pause in global warming (1): What do observations of the climate system tell us, 2013

A wide range of observed climate indicators continue to show changes that are consistent with a globally warming world, and our understanding of how the climate system works. Global mean surface temperatures rose rapidly from the 1970s, but have been relatively flat over the most recent 15 years to 2013. This has prompted speculation that human induced global warming is no longer happening, or at least will be much smaller than predicted. Others maintain that this is a temporary pause and that temperatures will again rise at rates seen previously. This paper is the first in a series of three reports from the Met Office Hadley Centre that address the recent pause in global warming and seek to answer the following questions. What have been the recent trends in other indicators of climate over this period; what are the potential drivers of the current pause; and how does the recent pause affect our projections of future climate? Weather and climate science is founded on observing and understanding our complex and evolving environment. The fundamental physics of the Earth system provides the basis for the development of numerical models, which encapsulate our understanding of the full climate system (i.e. atmosphere, ocean, land and cryosphere), and enable us to make projections of its evolution. It is therefore an inherent requirement that climate scientists have the best possible information available on the current state of the climate, and on its historical context. This requires highly accurate, globally distributed observations and monitoring systems and networks. This is also dependent on robust data processing and analysis to synthesise vast amounts of data, properly taking into account observational uncertainty resulting from both measurement limitations and observational gaps, in both space and time. Only through exercising due diligence and applying rigorous, unbiased, scientific assessment, can climate scientists provide the most complete picture on the state, trends and variability of the climate system’s many variables and phenomena. This provides the basis on which the science can advance the evidence and advice required by users. This document provides a short synthesis of that global picture as it stands today. A fuller briefing is produced in conjunction with vast numbers of scientists each year, and published in a Special Supplement to the Bulletin of the American Meteorological Society (BAMS) (Blunden and Arndt, 2013).

2019

Changes in climate are usually considered in terms of trends or differences over time. However, for many impacts requiring adaptation, it is the amplitude of the change relative to the local amplitude of climate variability which is more relevant. Here, we develop the concept of "signal-to-noise" in observations of local temperature, highlighting that many regions are already experiencing a climate which would be "unknown" by late 19th century standards. The emergence of observed temperature changes over both land and ocean is clearest in tropical regions, in contrast to the regions of largest change which are in the northern extratropics-broadly consistent with climate model simulations. Significant increases and decreases in rainfall have also already emerged in different regions with the United Kingdom experiencing a shift toward more extreme rainfall events, a signal which is emerging more clearly in some places than the changes in mean rainfall. Plain Language Summary Changes in climate are translated into impacts on society not just though the amount of change, but how this change compares to the variations in climate that society is used to. Here we demonstrate that significant changes, when compared to the size of past variations, are present in both temperature and rainfall observations over many parts of the world.

Scientific American, 2007

Science and Culture, 2020

This essay presents the basic science of global warming. At its base is human interference with the carbon cycle. Major current impacts, worldwide and in India, are discussed. We also present the latest science pertaining to the attribution of extreme events in India. Key to understanding climatic impacts in India is the excessive warming of the Indian Ocean. Planetary feedbacks and tipping points that are being crossed suggest that the urgency to intervene has never been greater.

The British Journal for the Philosophy of Science , 2015

The aim of the paper is to provide a clear and thorough conceptual analysis of the main candidates for a definition of climate and climate change. Five desiderata on a definition of climate are presented: it should be empirically applicable, it should correctly classify different climates, it should not depend on our knowledge, is should be applicable to the past, present and future and it should be mathematically well-defined. Then five definitions are discussed: climate as distribution over time for constant external conditions, climate as distribution over time when the external conditions vary as in reality, climate as distribution over time relative to regimes of varying external conditions, climate as the ensemble distribution for constant external conditions, and climate as the ensemble distribution when the external conditions vary as in reality. The third definition is novel and is introduced as a response to problems with existing definitions. The conclusion is that most definitions encounter serious problems and that the third definition is most promising.

ak-geomorphologie.de

2018

Climate change is a current issue nowadays. Scientific debates about this theme are rather common and the population in general is aware of the problem. These two words "climate change" seem to be everywhere. But how well are humans aware? Vox populi says "weather isn't what it used to be"! People can feel the changes. But what changes? "Climate is recorded, weather experienced" (Ingold and Kurtilla 2000: 187), so people only have the perception of the meteorological events occurred during their lifetime and probably they can only remember some, the ones that left a bigger impression. Weather changes are felt in daily or yearly basis. But climate? It is such a big picture. For instance, the idea of changes in the past is something vague associated with a distant Ice Age,