10 New Reconstructions Show Today’s Temperatures Still Among The Coldest Of The Last 10,000 Years
Even though CO2 concentrations hovered well below 300 ppm throughout most of the Holocene, newly published paleoclimate reconstructions affirm that today’s surface temperatures are only slightly warmer (if at all) than the coldest periods of the last 10,000 years. This contradicts the perspective that temperatures rise in concert with CO2 concentrations.
Bottom Graph Source: Rosenthal et al. (2013)
1. Even Past Cold Periods Were 0.5–1.5 °С Warmer Than Today
Nosova et al., 2018
“According to the present climate reconstruction, mid Holocene warming started only at 7,700 cal bp, with temperatures higher than now during the mid Holocene period. This warming was due to an increase in winter temperatures (1–5 °С higher than current), while summer temperatures remained relatively stable, with a July temperature<1 °С higher than now. … During the mid Holocene, two cold periods at 6,900–6,500 and at 5,300–5,000 cal bp were observed. Interestingly, during the cold periods, the temperatures exceeded the current ones by 0.5–1.5 °С.”
“The transition from the mid Holocene thermal maximum to the following period occurred without considerable climatic changes. The mean annual temperatures remained much higher than the current ones by 0.5–2.5 °С until 2,500 cal bp. Local maximum temperatures were observed at 4,800, 4,300, 3,500 and 2,900–2,700 cal bp. The present climatic reconstruction demonstrates a gradual cooling down to current levels at ca. 2,500 cal bp, and then followed by a new warming phase with up to 1–2 °С increase at approximately 1,500 cal bp.”
2. Only 3 Of 116 Holocene Temperature Anomaly Records Were Colder Than Today
Bajolle et al., 2018
“The mean annual temperature recorded at the closest meteorological station [La Sarre: 1961–1990] is 0.8 °C, with August temperature averages of 15.0 °C (1961–1990) and 15.4 °C (1981–2010). … During zone Lch1 (8500–5800 cal year BP), the average reconstructed temperature was 16.9 °C, with a decrease from 19 °C (maximum) to 17 °C at the end of the zone. In zone Lch-2 (ca. 5700–3500 cal year BP), temperatures had an average of 16.8 °C, with a decrease from 17.8 °C around 5200 cal year BP to 16.2 °C at 3400 cal year BP. Zone Lch-3 (ca. 3500–1200 cal year BP) started with inferences for high temperatures (19.3–18.5 °C), followed by a decrease to 16.8 °C between ca. 3000 and 2500 cal year BP. An increase (18.3 and 19.6 °C) was inferred for the period between 1800 and 1500 cal year BP. The average chironomid inferred temperature during Zone 3 was 17.9 °C. In the last zone (Lch-4), the temperatures decreased from ca. 17.5 °C at the beginning of the zone to 14.8 °C at the end of the zone. The average during this zone was 16.5 °C. The temperature anomalies show that throughout the whole record, only six of the inferences were colder than the climate normal of 15.4 °C and three were colder than today, with the climate normal of 15 °C (Fig. 4b). The average anomaly from 15 °C (2.10 °C) and from 15.4 °C (1.70 °C) for the whole record showed that the temperature inferences were generally, and significantly, warmer than today.”
3. New England (USA) Colder Now Than Nearly All Of The Last 11,000 Years
Oswald et al., 2018
4. Today’s Temperatures Still Just As Cold As The Global Little Ice Age
Coffinet et al., 2018
“This study represents the first detailed late Holocene quantitative air temperature reconstruction from the RVP [Rungwe Volcanic Province, southwestern Tanzania/East Africa] region. We identified a succession of cold/warm/cold events, largely in phase with the other regional East African climate records and with the cold periods identified worldwide by Wanner et al. (2011). This further supports that global scale processes may be the main drivers of the Holocene climatic variability. Moreover, warm conditions during the MCA [Medieval Climate Anomaly] followed by abrupt cooling during the LIA were observed at Kyambangunguru and elsewhere in East Africa suggesting that these two recent events occurred globally.”
5. Modern Temperatures -2.9°C Colder Than 7,000 Years Ago
Zhao et al., 2018
“According to the interpolation of meteorological data of the two nearest weather stations at Linxia (ca. 46 km away; MAT [mean annual temperature] = 7.3 °C) and Minhe (ca. 54 km away; MAT [mean annual temperature] = 8.3 °C)… In this study, we reconstructed mid-late Holocene climatic changes using GDGT distributions in a loess-paleosol sequence in the Lajia Ruins of the Neolithic Qijia Culture, Guanting Basin, in the southwestern end of the Chinese Loess Plateau. … MAT [mean annual temperature] decreased from 11.9 °C to 8.0 °C [today], during the past ca. 7000 yr, and a drastic decline in MAP [mean annual precipitation] (70 mm), accompanied by a 0.8 °C decline in MAT [mean annual temperature], occurred at 3800–3400 yr BP.”





