You vacation based on climate, but you pack based on weather
While 2014 was reported as the warmest year on record globally, the Great Lakes region experienced one of the coldest winters on record last year. What gives? The answer lies in the difference between weather and climate.
In early January, the National Oceanic and Atmospheric Administration (NOAA) reported that 2014 was the warmest year on record, with an annually-averaged temperature across global land and ocean surfaces 0.69 degrees Celsius (1.24 degrees Fahrenheit) above the 20th century average of 13.9 C (57.0 F). If living in the Midwest, this datum might seem strange given the colder-than-average winter last year. The difference can be explained by contrasting weather from climate.
While both terms refer to environmental variables or conditions such as temperature or humidity, weather amounts to short-term variations in these conditions of the atmosphere that we experience on a day-to-day, week-to-week, or month-to-month basis. The weather in the upper Midwest was record cold with above-average precipitation in many locations last year. On the other hand, climate is the average of daily weather conditions for an extended period of time, over a period of years, decades or centuries. NOAA differentiates the two this way (courtesy of Mark Twain): Climate is what you expect, weather is what you get.
Both weather and climate can be studied and tracked locally. Put differently, the difference between the two is in the scale of time, not the physical scale of local vs. global. Consider NOAA’s graphic showing land and ocean temperature percentiles for 2014. We see that the Midwest U.S. is blue, and if you experienced last winter here, the color alone makes you shiver! However, looking at the legend we see this is not a graphic showing temperature extremes or anomalies, it is showing annual average temperature relative to the long-term average for individual locations across the globe. Essentially, this graphic is showing the difference between weather and climate for 2014 (excluding precipitation, of course).
Visualizing the data in this way, it is easier to grasp that weather across the planet as a whole was warmer in 2014 than the climate expected based on historic conditions over more than a century.
Another take-away is that, like changing weather, climate change is experienced locally (regionally) in different ways. To borrow from the real estate world, climate change impact is all about location, location, location. To better understand these regional differences and more appropriately prepare for regional climate changes, NOAA established a national network of Regional Integrated Sciences and Assessments (RISAs) that focus on adaptation to climate change and variability. For the Great Lakes region, the Great Lakes Integrated Sciences and Assessments (GLISA) is the NOAA RISA.
The GLISA website includes compilations and summaries of scientific research from government organizations and major universities. One such resource is a fact sheet detailing Climate Change in the Great Lakes Region. We see that across the region, since 1900, annual average temperatures have increased by 2.0 F (1.1 C) and that by 2050, average air temperatures are projected to increase by an additional 1.8 to 5.4 F (1 to 3 C). These data are a combination of climatic observations and projections. What the weather will be next year is anyone’s guess, but the long-term climate trend in the Great Lakes region is warmer (and generally wetter). Remember, you vacation based on climate, but you pack based on weather!
For more information on climate trends and predictions for the Great Lakes region, explore the GLISA website in more depth, or contact a member of the Michigan State University Extension Climate Outreach Team.
"Wakati wa likizo, ""wakati wa likizo"" ni mwaka wa joto zaidi duniani, na ""wakati wa baridi"" ni mwaka wa baridi zaidi duniani." Ni nini kinachotoa? Jibu liko katika tofauti kati ya hali ya hewa na hali ya hewa. Shirika la National Oceanic and Atmospheric Administration (NOAA) limesema mwaka 2014 ulikuwa mwaka wenye joto zaidi kuwahi kurekodiwa, na wastani wa joto duniani kote ilikuwa 0.69 ° C (degrees Fahrenheit) juu ya wastani wa karne ya 20 wa 13.9 ° C (degrees Fahrenheit). Ikiwa unaishi katika Midwest, takwimu hii inaweza kuonekana ya ajabu kutokana na baridi kuliko wastani wa majira ya baridi mwaka jana. Tofauti hiyo yaweza kuelezwa kwa kutofautisha hali ya hewa na hali ya hewa. Wakati maneno yote mawili yanarejelea mabadiliko ya mazingira au hali kama vile joto au unyevu, hali ya hewa ni tofauti za muda mfupi katika hali hizi za anga ambazo tunapata kila siku, wiki, au mwezi. Hali ya hewa katika eneo la juu la Midwest ilikuwa baridi sana na mvua zaidi ya wastani katika maeneo mengi mwaka jana. Hali ya hewa ni wastani wa hali ya hewa ya kila siku kwa kipindi kirefu cha miaka, miongo au karne. NOAA inafafanua tofauti kati ya hali ya hewa na hali ya hewa kwa njia hii: Hali ya hewa ni kile unachotarajia, hali ya hewa ni kile unachopata. Hali ya hewa na hali ya hewa zinaweza kuchunguzwa na kufuatiliwa mahali hapo. Kwa maneno mengine, tofauti kati ya hizo mbili ni katika kiwango cha wakati, sio kiwango cha kimwili cha ndani dhidi ya kimataifa. NOAA inaonyesha asilimia ya joto la bahari na ardhi kwa mwaka 2014. Kwa mfano, katika eneo la Midwest, Marekani, ambapo majira ya baridi kali ya mwaka jana ilikuwa na rangi ya bluu, watu wengi walianza kuogopa. Hata hivyo, kuangalia hadithi hii, tunaona hii si grafu kuonyesha joto kali au anomalies, ni kuonyesha wastani wa joto ya kila mwaka ikilinganishwa na wastani wa muda mrefu kwa maeneo ya mtu binafsi duniani kote. Kwa mfano, picha hii inaonyesha tofauti kati ya hali ya hewa na hali ya hewa ya 2014 (bila mvua, bila shaka). Kwa kutafakari data kwa njia hii, ni rahisi kuelewa kwamba hali ya hewa duniani kote ilikuwa ya joto zaidi katika 2014 kuliko hali ya hewa inayotarajiwa kulingana na hali ya kihistoria kwa zaidi ya karne moja. Jambo jingine ni kwamba, kama vile mabadiliko ya hali ya hewa, mabadiliko ya hali ya hewa yanapatikana katika maeneo mbalimbali kwa njia tofauti. Kwa kukopa kutoka kwa ulimwengu wa mali isiyohamishika, athari za mabadiliko ya hali ya hewa ni juu ya eneo, eneo, eneo. Ili kuelewa tofauti hizi za kikanda na kujitayarisha kwa usahihi zaidi kwa mabadiliko ya hali ya hewa ya kikanda, NOAA ilianzisha mtandao wa kitaifa wa Sayansi na Tathmini za Mkusanyiko wa Mkoa (RISA) ambazo zinazingatia marekebisho ya mabadiliko ya hali ya hewa na kubadilika. Mkoa wa Maziwa Makuu: Utafiti wa Sayansi na Tathmini ya Maziwa Makuu (GLISA) Tovuti ya GLISA inajumuisha mkusanyiko na muhtasari wa utafiti wa kisayansi kutoka kwa mashirika ya serikali na vyuo vikuu vikuu. Mojawapo ya rasilimali hizo ni karatasi ya habari inayoelezea mabadiliko ya hali ya hewa katika Mkoa wa Maziwa Makuu. Tangu mwaka 1900, wastani wa joto la dunia umeongezeka kwa kiwango cha Fahrenheit 2.1 na kufikia mwaka 2050 wastani wa joto la hewa unatarajiwa kuongezeka kwa kiwango cha Fahrenheit 1.8 hadi 5.4 (Celsius 1 hadi 3). Takwimu hizo ni mchanganyiko wa uchunguzi wa hali ya hewa na makadirio. Hali ya hewa itakuwaje mwaka ujao ni mtu yeyote nadhani, lakini mwenendo wa muda mrefu wa hali ya hewa katika mkoa wa Maziwa Makuu ni joto (na kwa ujumla mvua). Kumbuka, wewe likizo kulingana na hali ya hewa, lakini wewe pakiti kulingana na hali ya hewa! Kwa habari zaidi juu ya mwenendo wa hali ya hewa na utabiri wa eneo la Maziwa Makuu, angalia tovuti ya GLISA kwa kina zaidi, au wasiliana na mwanachama wa Timu ya Ufikiaji wa Hali ya Hewa ya Chuo Kikuu cha Jimbo la Michigan.