In the paper, Ellis and Palmer make no direct mention of any implications of their work for future climate. How long does it actually take to melt a continental ice sheet? Five environmental variables, representing seasonal extremes of temperature, annual energy and moisture, and elevation, predicted 88% of continental variation in this variable. White, orange, and red dots correspond to temperate, subtropical, and tropical communities, respectively. THE ESCALATOR Climate variability includes all the variations in the climate that last longer than individual weather events, whereas the term climate change only refers to those variations that persist for a longer period of time, typically decades or more. It is rather convoluted. Climate changes that occurred after the widespread deployment of measuring devices, can be observed directly. This can affect both global and local patterns of climate and atmosphere-ocean circulation. [118] During the event large amounts of methane was released, a potent greenhouse gas. Early geologists therefore named apparent sequences of glacial and interglacial periods of the Quaternary Ice Age after characteristic geological features, and these names varied from region to region. Some of the variability does not appear to be caused systematically and occurs at random times. The paper says that increased CO2 leads to more greening of the planet and thus less dust on the ice sheets, and so a cooling effect (parpahrasing). Skeptical Science New Research for Week #44 2022, Climate Change's Controversial Policy: Loss & Damage, How sea level rise contributes to billions in extra damage during hurricanes, Scientists probe newly discovered methane emissions, 2022 SkS Weekly Climate Change & Global Warming News Roundup #43, Skeptical Science New Research for Week #43 2022, World rocked by 29 billion-dollar weather disasters in 2022, Climate change made 2022s northern-hemisphere droughts at least 20 times more likely, 2022 SkS Weekly Climate Change & Global Warming News Roundup #42, Skeptical Science New Research for Week #42 2022, Building a better hurricane cone of uncertainty, What can YOU do about climate change? For example, the megafaunal extinctions of the late Pleistocene were driven by, together with human impacts, climate forcing (see Fig. If Ellis and Palmer had realized this, they could have cut their CO. Radiometric dating uses the properties of radioactive elements in proxies. Test your knowledge of this "hot" topic with this quiz. The overall CO2 level influences whether climate will respond to Milankovitch cycles by producing glacial/interglacial cycles, but it does not cause the individual glacial/interglacial periods. We also have multiple areas of ice accumulation each with its own patterns of precipitation sources. The melt pattern is quite complex. Oikos 65: 514527. [128], Hemispheres. The Last Glacial Period (LGP), also known colloquially as the last ice age or simply ice age, occurred from the end of the Eemian to the end of the Younger Dryas, encompassing the period c. 115,000 c. 11,700 years ago. [14] A major part of carbon dioxide emissions were soon dissolved in water and built up carbonate sediments. In North America, mammal communities were significantly altered, with roughly 70 of the largest 220 mammals becoming extinct [113,114]. Fig. Pakistans End of Days 2022 monsoon season, 2022 SkS Weekly Climate Change & Global Warming News Roundup #40, No, a cherry-picked analysis doesnt demonstrate that were not in a climate crisis, Skeptical Science New Research for Week #40 2022, From the eMail bag: A Review of a paper by Ellis and Palmer. Walker, M., Johnsen, S., Rasmussen, S. O., Popp, T., Steffensen, J.-P., Gibbard, P., Hoek, W., Lowe, J., Andrews, J., Bjo rck, S., Cwynar, L. C., Hughen, K., Kershaw, P., Kromer, B., Litt, T., Lowe, D. J., Nakagawa, T., Newnham, R., and Schwander, J. An increase in species richness with decreasing latitude is the pattern generally observed at three spatial scales, including the level of broad climatic zones (Figure 3), assemblages occupying arbitrary geographic subdivisions (i.e., quadrats or bands) of the earth's surface (Figure 4), and local ecological communities (Figures 4 and 5). A more specific definition would state that climate is the mean state and variability of these features over some extended time period. One example of radiometric dating is radiocarbon dating. A tree-ring record is established by compiling information from many living trees in a specific area. The temperature changes occurred somewhat suddenly, at carbon dioxide concentrations of about 600760 ppm and temperatures approximately 4C warmer than today. The scientific development of chemicals that can be profitable did not include an indepth investigation of the more complex potential for harm to be done (that is difficult because of the complexity, and it would be expensive and take time). "the paper[argues] that low CO2 leads to low vegetation, which leads to increased dust" How does this comport with general knowledge? James Hansen suggested that humans emit CO2 10,000 times faster than natural processes have done in the past. Changes in populations are influenced by climatic trends and also extreme events, sea-ice decrease and glacier retreat, as well as permafrost and snow cover changes. When regression models are significant, the contribution of linear (b1) or quadratic (b2) terms are indicated by superscripts (NS, p>0.05; *, 0.05p >0.01; **, 0.01p>0.001; ***, p>0.001); percent variation in a component of taxonomic biodiversity that is related to latitude is quantified by R2. Human changes of the composition of the atmosphere or land use. What are Sand Dunes? [4], The scientific study field of paleoclimatology began to further take shape in the early 19th century, when discoveries about glaciations and natural changes in Earth's past climate helped to understand the greenhouse effect. ScienceDirect is a registered trademark of Elsevier B.V. ScienceDirect is a registered trademark of Elsevier B.V. Encyclopedia of Biodiversity (Second Edition), Willig and Selcer, 1989; Kaufman and Willig, 1998; Stevens and Willig, 2002. Continental glaciers typically accumulate mass well away from ocean sources of moisture, and flow towards the oceans. (If they are big enough, they can make their own hill.). For example, annual killifishes of the genus Nothobranchius inhabit seasonal wetland pools in African savanna. Over a longer period of 22Ma, fossil rodent communities from central Spain responded to climate impacts with pulses of species turnover at 12Ma intervals coinciding with astronomical climate forcing associated with Milankovitch oscillations [115]. The IPCC reports give extensive coverage to past climates, for this specific purpose. It takes centuries or millennia to grow them. Latitudinal gradients of local and regional species richness for New World bats. So, in order to make their about a third comparison, you need to compare bee metabolism in W to a bogus 0.006W/m2/decade. This simple idea had its genesis in the work of Terborgh (1973), with considerable development and refinement by Rosenzweig (1995) in subsequent years, during which the effects of productivity and zonal bleeding have been incorporated into a more comprehensive conceptual model. So, like the flying bee example, Ellis and Palmer choose to do a unit conversion and calculation that favours the conclusion they want to support, without really justifying the logic. [117] During the PETM, a mass extinction of organisms in the deep ocean took place.[120]. No actual climate model to provide precipitation inputs or melt processes, or glacier dynamics models to accumulate ice and move it from zones of accumulation to zones of melt. For instance, the deep marine record, the source of most isotopic data, exists only on oceanic plates, which are eventually subducted: the oldest remaining material is 200 million years old. There is very little change to the area-averaged annually averaged sunshine; but there can be strong changes in the geographical and seasonal distribution. First, larger biotic provinces, regardless of latitude, have more taxa than do their smaller counterparts (e.g., generic, familial, and ordinal richness of mammals increases with provincial area). [115] When there is a lot of sea ice present globally, especially in the tropics and subtropics, the climate is more sensitive to forcings as the icealbedo feedback is very strong.[116]. For instance, we are now in a period of anthropogenic global warming. This is similar to the precession of a spinning top, with the axis tracing out a pair of cones joined at As a consequence, glaciers worldwide have been found to be shrinking significantly. (Reprinted by permission from Nature 365, 636639 (1993) Macmillan Magazines Ltd.). [53], The US Geological Survey estimates are that volcanic emissions are at a much lower level than the effects of current human activities, which generate 100300 times the amount of carbon dioxide emitted by volcanoes. When plants then use this carbon to grow, this isotope is not replenished anymore and starts decaying. So many important factors are ignored or dismissed with a wave of the hands. During the Pleistocene, cycles of glaciations and interglacials occurred on cycles of roughly 100,000years, but may stay longer within an interglacial when orbital eccentricity approaches zero, as during the current interglacial. [81][82] During the Carboniferous period, about 300 to 360 million years ago, plate tectonics may have triggered large-scale storage of carbon and increased glaciation. In contrast, finer resolution of zones to tropical, subtropical, temperate, boreal, and tundra indicates the areal predominance of tropical lands globally. The atmosphere is influenced by and linked to other features of Earth, including oceans, ice masses (glaciers and sea ice), land surfaces, and vegetation. To address the question of how much solar radiation the globe absorbs (which is the proper question for looking at global climate), you need to consider all of the globe - each latitude, each day, and each individual surface cover. [8][9], Within climatic geomorphology one approach is to study relict landforms to infer ancient climates. [110] Shaped by orbital variations, responses such as the rise and fall of continental ice sheets and significant sea-level changes helped create the climate. Certain feedbacks involving processes such as clouds are also uncertain; for contrails, natural cirrus clouds, oceanic dimethyl sulfide and a land-based equivalent, competing theories exist concerning effects on climatic temperatures, for example contrasting the Iris hypothesis and CLAW hypothesis. Latitudinal gradients suggest that arctic plant diversity is sensitive to climate (Callaghan etal., 2005). The locations of the seas are important in controlling the transfer of heat and moisture across the globe, and therefore, in determining global climate. Which gases play an important role in climate change? [61] Solar output varies on shorter time scales, including the 11-year solar cycle[62] and longer-term modulations. Together, they make up an integrated Earth system, in which all components interact with and influence one another in often complex ways. Once you have snow that survives a summer, you get a perennial snow patch, but it takes more to get a glacier. It takes centuries or millennia to grow them. Ice-coring projects in the ice caps of Greenland and Antarctica have yielded data going back several hundred thousand years, over 800,000 years in the case of the EPICA project. Climatological temperatures substantially affect cloud cover and precipitation. The change in species diversity with latitude for Atlantic deep-sea (a) isopods, (b) gastropods; and (c) bivalves. This thermal niche conservatism is likely driven by ecological niche conservatism, as mammals track particular habitat during climatic change [29]. [15] About 3.4 billion years ago, nitrogen was the major part of the then stable "second atmosphere". Moreover, considerable controversy surrounds the mechanisms that affect latitudinal patterns in richness, with ecological, evolutionary, historical, and stochastic processes (Table 1) championed as the cause(s) of observed gradients (Rohde, 1992). The 18O of coralline red algae provides a useful proxy of the combined sea surface temperature and sea surface salinity at high latitudes and the tropics, where many traditional techniques are limited. refer to Li et al. ", National Centers for Environmental Prediction, "Part of the Pacific Ocean Is Not Warming as Expected. A tree-ring record can be used to produce information regarding precipitation, temperature, hydrology, and fire corresponding to a particular area. In addition, latitudinal gradients have not been consistent through time, being primarily restricted to the Paleozoic and the past 30 million years (i.e., times of colder climates). Combined with techniques to date the proxies, the paleoclimate records are used to determine the past states of Earth's atmosphere. Strong positive relationships between growth and temperature are observed not only in dwarf shrubs such as willows (Salix sp.) In addition, species richness increases toward the tropics for many focal scales (Fig. Once you have snow that survives a summer, you get a perennial snow patch, but it takes more to get a glacier. Considerable debate continues about the relative importance of mechanisms that may contribute to latitudinal biodiversity gradients, with ecological, evolutionary, historical, and stochastic processes championed as the principal causes by different researchers (Table 1). The Ellis and Palmer focus on variations in solar input on the summer solstice at 65N ignores virtually all of this. The opposite effect is volcanism, responsible for the natural greenhouse effect, by emitting CO2 into the atmosphere, thus affecting glaciation (Ice Age) cycles. Recent remote-sensing records indicate a greening of the Arctic, suggesting increased photosynthetic activity and net primary productivity, mostly through shrub expansion (Sturm etal., 2001), although this process is somewhat slower in the High Arctic (Jia etal., 2003). Second, northern and southern tropical zones are adjacent, whereas the northern and southern variants of other latitudinally defined zones are isolated from each other. [2], The term climate change is often used to refer specifically to anthropogenic climate change (also known as global warming). When they get large enough, glaciers will flow downhill. While individual species at particular localities may change with climate (tracking their particular niche), the trophic structure of the mammal community remains similar through a shuffling of community composition and relative abundances [28,29]. Examples include variability in ocean basins such as the Pacific decadal oscillation and Atlantic multidecadal oscillation. Finally, it should be noted that most of the current knowledge on the Arctic floristic evolution and diversity is based on studies of vascular plants. As the Proterozoic Eon drew to a close, the Earth started to warm up. At this time vast rainforests covered the equatorial region of Europe and America. Part of what they do is summarized in table 4 of their paper, where they list reductions in CO2 affecting treeline. Long-term averages and variability of weather in a region constitute the region's climate. Note that we have two radical inconsistencies in units here: the CO2 radiative forcing is per square metre (so we need to account for the area of the earth to get total watts), and we have the per decade obfuscation. Something obvious seems to have been missed here. In this case even a small summer warming may lead to a shift towards plant communities that are compositionally and functionally characteristic of more southern subzones (Walker etal., 2008). A Finnish study, however, reported a general decline in macrophyte richness in lakes towards the north (Linkola, 1933; reported in Rorslett, 1991), related to the duration of the ice-free period since short growing seasons may not only limit macrophyte growth but their distribution as well (Heino, 2001). Much work has been done to explain the climatological and geological aspects of glacial/interglacial cycles. Something obvious seems to have been missed here. Some changes in climate may result in increased precipitation and warmth, resulting in improved plant growth and the subsequent sequestration of airborne CO2. For example, in Africa, species-rich small barbs (i.e., Enteromius spp., Cyprinidae) do not rely on flood pulses and have often evolved into local endemics. They argue against a straw man: that mainstream climate science thinks that CO2 is supposed to force the glacial/interglacial cycles. In section 5, they give their hypothesis how low CO2 leads to reductions in vegetation cover, and how this is what leads to high dust concentrations that accumulate on the ice/snow of the glaciers. Modified from Stevens RD and Willig MR (2002) Geographical ecology at the community level: perspective on the diversity of New World bats. [5], On the broadest scale, the rate at which energy is received from the Sun and the rate at which it is lost to space determine the equilibrium temperature and climate of Earth. Glaciers will have an accumulation zone, where precipitation exceeds melt, and an ablation zone, where melt exceeds precipitation. Let us know if you have suggestions to improve this article (requires login). Yet another study in North European lakes demonstrated no or only marginal latitudinal changes in macrophyte diversity (Rorslett, 1991), coinciding with the lack of latitudinal pattern in submerged macrophyte species richness in 83 South American shallow lakes (S. Kosten et al., unpublished data). The Rapp et al paper also seems to be rather confused about CO2 as a feedback vs. CO2 as a forcing. About 0.1g, so the metabolic rates work out to a range of 0.01-0.08W per bee. Interestingly, in the caption to their figure 1, they use the phrase CO2 concentration follows global temperatures very closely, giving the illusion of CO2 being the primary causal feedback factor. [Emphasis mine] That illusion is supported by detailed climate and glacier dynamics models and extensive analysis in the scientific literature. In spite of these weaknesses, Ellis and Palmer have the hubris to finish their introduction with the statement And while this proposal represents a reversal of conventional thinking it does explain each and every facet of the glacial cycle, and all of the many underlying mechanisms that control its periodicity and temperature excursions and limitations. They think that their proposed mechanism is an explanation of Life, the Universe, and Everything glacial. [99] Remains of beetles are common in freshwater and land sediments. Glaciers have a mass balance the difference between winter accumulation of precipitation, and the losses due to summer evaporation/sublimation and movement of the glacier. [12], The field of geochronology has scientists working on determining how old certain proxies are. The explanation is not obvious, as productivity tends to increase northward. There are two potential mechanisms that might cause this relationship. They are quasiperiodic (not perfectly periodic), so a Fourier analysis of the data does not have sharp peaks in the spectrum. [94] Stress, too little precipitation or unsuitable temperatures, can alter the growth rate of trees, which allows scientists to infer climate trends by analyzing the growth rate of tree rings. lithospheric plates refer to the blocks of the landmass. In general, species richness increases from polar to tropical regions (Willig et al., 2003; Hillebrand, 2004) for most taxonomic groups (e.g., mammals, birds, reptiles, amphibians, fish, tunicates, crustaceans, mollusks, brachiopods, corals, foraminiferans, and vascular plants) and geographical settings (e.g., Africa, North and South America, the Atlantic Ocean). Of course, the reason why the discipline of climatology looks at past climates is due to the old adage "the past is the key to the future". [10] Being often concerned about past climates climatic geomorphology is considered sometimes to be a theme of historical geology. They use CO2 values of 150 for alpine treeline (2000m altitude), and 115 for tropical treeline (4000m altitude). but you need to carefully read the table to notice that they are using CO2 values in bar, not ppm. Box 6.2: What Caused the Low Atmospheric Carbon Dioxide Concentrations During Glacial Times? [6] The international ice core community has, under the auspices of International Partnerships in Ice Core Sciences (IPICS), defined a priority project to obtain the oldest possible ice core record from Antarctica, an ice core record reaching back to or towards 1.5 million years ago.[7]. You have to read the paper to try to follow the logic (as such) of their argument about CO2 and temperature. In what ecosystem is CO2 the limiting factor deserts? The paper says that increased CO2 leads to more greening of the planet and thus less dust on the ice sheets, and so a cooling effect (parpahrasing). Section 2 of their paper discusses the Milankovitch cycles, and introduces their "see - huge difference in input of energy on summer solstice at 65N" calculation. In section 5, they give their hypothesis how low CO2 leads to reductions in vegetation cover, and how this is what leads to high dust concentrations that accumulate on the ice/snow of the glaciers. It has been postulated that ionized particles known as cosmic rays could impact cloud cover and thereby the climate. There is a gradual increase in species richness following the increase in food supply from the equator northward.
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