Iqlim o'zgarishi ilm-fanning muhim sohasidir. Biroq, barcha fanlar kabi, u ham aniq fan emas. Iqlimshunoslik fanlarini tushunish doimo o'zgarib turadi. Iqlim o'zgarishi yangi emas: u har doim bo'lgan, va har doim bo'ladi. Buning misoli sifatida global haroratning uzoq muddatli pasayishi davri bo'lgan Muz davri ko'rsatilishi mumkin.

Climatic change is an important field of study in science. However, as with all sciences, it is not an exact science. The understanding of the climatic sciences is always changing. Climate change is not new, there has always been climate change, and there will always be climate change. The period known as the Ice Age, which was a long-term period of reduction in global temperatures is an example of this.

Global isinish va iqlim o‘zgarishi o‘rtacha global haroratning ko‘tarilishini anglatadi. Tabiiy hodisalar va inson faoliyati o‘rtacha global haroratning ortishiga hissa qo‘shadi, deb hisoblanadi — bu hozirgi kunda jiddiy bahs-munozaralar mavzusi. Bu asosan issiqxona effektining kuchayishi natijasida yuz beradi, ya’ni atmosferadagi ba’zi gazlar energiyani ushlab qolganda Yer yuzasida harorat ko‘tariladi. Bunday gazlarga karbonat angidrid (CO2) kiradi. Isinishning so‘nggi davri Sanoat inqilobi bilan ham to‘g‘ri kelgan, bu davrda inson tomonidan chiqarilgan CO2 eng yuqori darajaga yetgan. Shu sababli Al Gore kabi ko‘plab kishilar CO2 darajasining ko‘tarilishini harorat ko‘tarilishi bilan solishtirib, Yer atmosferasidagi CO2 ortishi haroratning ko‘tarilishida hal qiluvchi omil bo‘lgan, degan xulosaga kelganlar. CO2 va harorat o‘rtasidagi bog‘liqlik global isinishning asosiy sababi hisoblanadi, biroq bu qarash yakuniy emas va bu xulosa uchun foydalanilgan namunalarda bir qator muammolar mavjud.

Global warming and climate change refer to an increase in average global temperatures. Natural events and human activities are believed to be contributing to the increase in average global temperatures – this is the area of current considerable debate. This is caused primarily by increases in the greenhouse which is the rise in temperature on Earth as certain gases in the atmosphere trap energy gases such as Carbon Dioxide (CO2). This latest warming period has also coincided with the Industrial Revolution, which saw the greatest output of human induced CO2, leading many, like Al Gore, to compare the rise in CO2 levels with the rise in temperatures, drawing a conclusion that the rise in CO2 in the earth’s atmosphere was the determining factor in the rise in temperatures. The CO2-temperature connection is considered the dominant cause for global warming, however this view is not conclusive and there is a number of issues with the samples used for this conclusion.

Har bir necha yilda BMTning Hukumatlararo iqlim o‘zgarishi bo‘yicha panelidagi (IPCC) yetakchi iqlim olimlari iqlim o‘zgarishini tushunishdagi yutuqlarni batafsil bayon etuvchi yirik hisobotlarni e’lon qilib kelmoqdalar. Ular boshidanoq emissiyalarni kamaytirish zarurligini tavsiya qilib kelgan. Bu organ dunyoning turli mamlakatlaridan kelgan yuzlab iqlim olimlaridan tashkil topgan. 2007 yilning yanvar oyi boshida IPCCning to‘rtinchi yirik hisoboti shuni umumlashtirdiki, ilmiy tushunchaning yaxshilanishi tufayli ular inson omili bilan yuzaga kelayotgan iqlim o‘zgarishiga avvalgidan ham ishonchliroq bo‘lishgan. Hisobotda shunday deyilgan: “Antropogen isish va sovitish omillarining iqlimga ta’siri haqidagi tushuncha Uchinchi baholash hisobotidan (TAR) keyin yaxshilangan bo‘lib, bu 1750 yildan beri inson faoliyatining global o‘rtacha sof ta’siri isish bo‘lganligiga juda yuqori ishonch bildirishga imkon bermoqda.” Ularning “juda yuqori ishonch” va “juda ehtimoliy” ta’riflari to‘g‘ri bo‘lish ehtimoli 90% ekanligini bildiradi (ularning 2001 yildagi hisoboti 66% ishonchni da’vo qilgan edi).

Every few years, leading climate scientists at the UN’s Intergovernmental Panel on Climate Change (IPCC) have released major reports detailing the progress in understanding climate change. From the outset they have recommended that there be emission reductions. This body is comprised of hundreds of climate scientists from around the world. At the beginning of January 2007, the IPCC’s fourth major report summarised that they were even more certain than before of human-induced climate change because of better scientific understanding; ‘The understanding of anthropogenic warming and cooling influences on climate has improved since the Third Assessment Report (TAR), leading to very high confidence that the globally averaged net effect of human activities since 1750 has been one of warming.’ Their definition of “very high confidence” and “very likely” is a 90% chance of being correct (their 2001 report claimed a 66% certainty).

Tarixiy emissiyalar nuqtai nazaridan olganda, sanoatlashgan mamlakatlar bugungi kunga qadar atmosferadagi karbonat angidrid to‘planishining taxminan 80 foizini tashkil etadi. 1950-yildan beri AQSh jami taxminan 50,7 milliard tonna uglerod chiqarganki, Xitoy esa (aholisi 4,6 barobar ko‘p bo‘lsa-da)

In terms of historical emissions, industrialised countries account for around 80% of the carbon dioxide build-up in the atmosphere to date. Since 1950, the US has emitted a cumulative total of roughly 50.7 billion tons of carbon, while China (4.6 times more populous)

va Hindiston (aholisi 3,5 barobar ko'p) esa mos ravishda atigi 15,7 va 4,2 milliard tonna chiqindi chiqargan. Har yili jahon sanoat karbonat angidrid chiqindilarining 60 foizdan ortig'i aholisining taxminan 20 foizi yashaydigan sanoatlashgan mamlakatlardan kelib chiqadi.

and India (3.5 times more populous) have emitted only 15.7 and 4.2 billion tons respectively. Annually, more than 60% of global industrial carbon dioxide emissions originate in industrialized countries, where only about 20% of the world’s population resides.

Rivojlangan dunyoda emissiyalarning o'sishining katta qismi sanoat inqilobi davridagi tez sanoatlashuvdan kelib chiqadi. 14 trillion dollarlik iqtisodiyotga ega AQSh dunyodagi eng yirik ifloslantiruvchi davlat bo'lib, emissiyalarni kamaytirish maqsadlari bo'yicha har qanday kelishuvga to'siq bo'lib kelmoqda. Emissiyalarni kamaytirish G'arbdagi sanoat kamroq mahsulot ishlab chiqarishini talab qiladi – bu esa G'arb iqtisodiyotlarining o'sish o'rniga qisqarishiga olib keladi. Kapitalizmda iste'molni kamaytirish "shirk" deb hisoblanadi. Shu bilan birga, rivojlangan mamlakatlarda qazilma yoqilg'ilar iste'moli darajasi dunyoning qolgan qismiga nisbatan ham juda yuqori. Qayta tiklanmaydigan resurslarning tugashi va atrof-muhitning vayron bo'lishi asosan AQSh iste'mol namunalari tufayli yuzaga keladi. AQShning qazilma yoqilg'i iste'moli global o'rtacha ko'rsatkichdan besh barobardan ancha yuqori.

Much of the growth in emissions in the developed world stem from rapid industrialisation from the industrial revolution era. The US with its $14 trillion economy is the world’s largest polluter and has acted as an obstacle to any agreement on emission reduction targets. Reducing emissions would mean industry in the West would need to produce less – this would lead to economies in the West shrinking rather than growing. To reduce consumption is considered ‘Shirk’ in Capitalism. By the same token, the rate of consumption of fossil fuels in developed countries is also extremely high relative to the rest of the world. The depletion of nonrenewable resources and environmental destruction is primarily caused by the consumption patterns of the US. US consumption of fossil fuels is well over five times the global average.