Home Arguments Software Resources Comments Consensus Project Translations About Donate TwitterFacebookYouTubePinterestRSS PostsRSS CommentsEmail Subscribe Climate's changed sun bad consensus cooling Models unreliable Temp record unreliable Animals plants adapt hasn't warmed 998 Antarctica gaining ice View Arguments Username Password Keep logged New? Register Forgot password? Latest Posts Archives Climate Hustle IPCC global surface warming projections accurate science Global surface temperature measurements range IPCC projections. Climate Myth IPCC global warming projections wrong Yet leaked report extraordinary concession past years, recorded world temperatures increased quarter rate IPCC claimed published last assessment 2007. Back then, observed warming years 990-2005 taken place rate 0.2C per decade, predicted would continue 20 years, basis forecasts computer climate models. report observed warming recent years 2012 0.05C per decade computer predictions." (David Rose) figure 2013 Intergovernmental Panel Climate Change (IPCC) report compares global surface warming projections 990, 995, 2001, 2007 IPCC reports temperature measurements. IPCC AR5 Figure .4. Solid lines squares represent measured average global surface temperature changes NAS (blue).
NO (yellow), UK Hadley Centre (green). colored shading shows projected range surface warming IPCC First Assessment Report (FAR; yellow), Second (SAR; green), Third (TAR; blue), Fourth (AR4; red). IPCC AR5 Figure .4. Solid lines squares represent measured average global surface temperature changes NAS (blue), NO (yellow), UK Hadley Centre (green). colored shading shows projected range surface warming IPCC First Assessment Report (FAR; yellow), Second (SAR; green), Third (TAR; blue), Fourth (AR4; red). 990, global surface temperatures warmed rate 0.15°C per decade, range model projections 0.10 0.35°C per decade. IPCC notes. global climate models generally simulate global temperatures compare observations climate timescales ... 990–2012 data shown consistent [1990 IPCC report] projections, consistent zero trend 990 ... trend globally-averaged surface temperatures falls range previous IPCC projections. Naysayers? weeks months leading publication final 2013 IPCC report, flood opinion articles blogs mainstream media claiming models used IPCC dramatically over-predicted global warming thus failure.
This narrative clearly conflicts IPCC model-data comparison figure shown above, what's going on? mistaken climate contrarian articles suffered combination errors. ) Publicizing flawed draft IPCC model-data comparison figure Late last year, early draft IPCC report leaked, including draft version figure shown above. version graph flaws, including significant immediately noted statistician climate blogger Tamino. flaw this: series (both projections observations) aligned 990. observations include random year-to-year fluctuations, whereas projections average multiple models averages ... projections aligned value due existing trend observations 990. Aligning projections single extra-hot year projections seem hot, observations cool comparison. draft version IPCC figure, simply visual illusion surface temperature data appeared warming less slowly model projections, measured temperature trend fell range model simulations. Obviously mistake subsequently corrected. This illustrates bad idea publicize material draft form, definition work progress. 2) Ignoring range model simulations single model simulates possible future climate outcome. reality, infinite number possible outcomes, depending various factors greenhouse gas emissions natural climate variability change. This climate modelers predictions; projections, say scenario 'x', climate change 'y' fashion.
shaded regions IPCC figure represent range outcomes individual climate model simulations. IPCC illustrates "multi-model mean," averages together individual model simulation runs. This average easy comparison observational data; however, there's believe climate follow average path, especially short-term. natural factors act amplify human-caused global surface warming, 990s, climate likely warm faster model average short-term. natural factors act dampen global surface warming, 2000s, climate likely warm slowly model average. model simulations averaged together, random natural variability individual model runs cancel out, steady human-caused global warming trend remains left over. reality climate behaves single model simulation run, average model runs. This important retain shaded range individual model runs. 3) Cherry Picking claims IPCC models failed based surface temperature changes past years (1998–2012). During period, temperatures risen 50 percent slowly multi-model average, remained range individual model simulation runs. However, 998 represented abnormally hot year Earth's surface due strongest El Niño events.
20th century. Thus represents poor choice starting date analyze surface warming trend (selectively choosing convenient start and/or points known 'cherry picking'). For example, select different 5-year period, 992–2006, surface warming trend nearly 50 percent faster multi-model average, statistician Tamino helpfully illustrates figure below. Fast warming trend 992–2006, slow warming trend 997–2012. Global surface temperature data 975–2012 NAS linear trend (black), trends 992–2006 (red) 998–2012 (blue). short, climate contrarians declaring global surface warming accelerating control 2006, business declaring global surface warming 'paused' 2013. Both statements equally wrong, based cherry picking noisy short-term data. IPCC models accurate. For 992–2006, natural variability climate amplified human-caused global surface warming, dampened surface warming 997–2012. Over full period, overall warming rate remained range IPCC model projections, 2013 IPCC report notes.
long-term climate model simulations show trend global-mean surface temperature 951 2012 agrees observed trend (very confidence). are, however, differences simulated observed trends periods short years (e.g., 998 2012). IPCC notes climate models accurately simulated trends extreme cold heat, large-scale precipitation pattern changes, ocean heat content (where global warming goes). Models better simulate Arctic sea ice decline, previously dramatically underestimated. all, IPCC models impressive job accurately representing projecting changes global climate, contrary contrarian claims. fact, IPCC global surface warming projections performed better predictions climate contrarians. important remember weather predictions climate predictions different. harder predict weather further future. With climate predictions, short-term variability (like unpredictable ocean cycles) predictions difficult. actually better predicting climate changes several decades future, time short-term fluctuations average out. That's climate models hard time predicting changes 0–15 years, predictions several decades future, IPCC illustrates.
This news, climate change, long-term changes worried about: IPCC surface temperature change projections IPCC AR5 projected global average surface temperature changes emissions scenario (RCP8.5; red) emissions scenario (RCP2.6; blue). Intermediate rebuttal written dana1981 Update July 2015: Here related lecture-video Denial101x Making Sense Climate Science Denial Last updated July 2015 pattimer. View Archives Printable Version | Offline PDF Version | Link page Comments Comments : sailing 01:57 AM September, 2017 Nice work! would convincing record temperatures 2014, 2015, 2016 plotted. Post Comment Political, off-topic ad hominem comments deleted. Comments Policy. logged post comment. Login left margin new, register here. © copyright 2018 if john if cook if home if links if translations if about if us if contact us