Shock outlook for local weather

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A global map of when cities can expect climate change to affect local climates drastically Image: Mora et al, University of Hawaii
A world map of when cities can expect global warming to have a drastic effect on local climates
Image: Mora et al, University of Hawaii

 By Tim Radford

Detailed new research into when global warming will start to have a serious effect on local climates has produced the shock finding that it could happen much sooner than scientists have previously predicted

London, 9 October – Catastrophic climate change may begin sooner than anyone expected ­­– and the first place to feel the heat could be a small but important city in Indonesia. By 2020, oceanographers and climate scientists warn, rising air temperatures around Manokwari in West Papua could trigger a new climate regime.

Dr Camilo Mora and research colleagues at the University of Hawaii report today in Nature that they looked at the question of when global warming would begin to alter local climates. And they admit that they were shocked by the results of their calculations.

Weather is what happens every day – gentle rain, torrential rain, heat waves, cold snaps, and so on. Climate is the range and pattern of these turbulent events over a generation or so.

For more than two decades, climate scientists have been warning that increasing greenhouse gas emissions will change climate inexorably. Increasingly – one of the most recent cases reported was in August this year – researchers have warned that, by mid-century, the world could move into a regime in which, in some continental locations, even the coolest summer days will be hotter than the hottest days experienced now.

Future warming

Such warnings are general: they define what will happen on average. But Mora and colleagues were concerned with specifics. So they used 39 climate models or computer simulations of climate change, plus climate records of observed change from 1860 to 2005, to compose a new map of future warming around the planet.

They considered variables such as precipitation, evaporation, ocean surface temperature and the chemistry (the pH) of the seas.  And they made assumptions – one of which was that the world would go on burning natural gas, coal and oil, manufacturing cement, clearing forests and so on at an increasing rate.

Their calculations told them that, if that was so, then air temperatures worldwide would rise to force a new climate regime – that is, the climate pattern would shift continuously beyond the most extreme records experienced in the past 150 years. And the date for this tipping point would be 2047.

However, 2047 represents a mean – a date arrived at by defining the average. So some places will feel the big heat well ahead of 2047, while many others will be affected decades later.

The scientists therefore went for greater detail. Which is why Manokwari, a metropolitan area of fewer than 300,000 people, and home to 24 distinct tribal groups, each with its own language and culture, looks set to make history.

It will, according to the scientists’ calculations, start to experience climate change in just seven years from now. By 2020, the local climate will be consistently hotter, and the local rainfall patterns could alter.

“The results shocked us . . . Within my generation, whatever climate we were used to will be a thing of the past.”

Dr Mora admitted: “The results shocked us. Regardless of the scenario, changes will be coming soon. Within my generation, whatever climate we were used to will be a thing of the past.”

Other tropical and subtropical cities will start to share the Manokwari experience a little later. Things will become increasingly uncomfortable in Lagos by 2029, in Mexico City by 2031, and Cairo by 2036.  Moscow, which has already recorded unprecedented heat waves this century, will experience permanent change in 2063. Reykjavik will remain relatively untroubled until 2066.

The finding, to an extent, upsets some expectations about the impact of global warming. For a quarter of a century, climate scientists have warned that the fastest changes will be in the Arctic, and the loss of sea ice has been dramatic.

But the tropics are home to the greatest concentrations of biodiversity – the coral reefs, rain forests and savannas – and also to the greatest numbers of the poorest people.

Vulnerable to change

Tropical plants and animals are finely adapted to environmental conditions, and vulnerable to change; coral reefs and plants in particular can hardly migrate. Crop plants, too, are sensitive to extremes of heat, and so are water supplies. The implications are that at least a billion people – and possibly very many more – could find themselves increasingly short of food and water, and with ever greater strains on sanitation and health systems.

Swift and determined action to stabilise emissions could delay the tipping point and give more nations time to adapt, but the bad news is that such action could now only delay the mean date to 2069 – and the developing nations in the tropics would still be first in the firing line.

“Our results suggest that countries first impacted by unprecedented climates are the ones with the least capacity to respond,” said Ryan Longman, one of the co-authors of the study. “Ironically, these are countries that are least responsible for climate change in the first place.”Climate News  Network

Projected Year of Climate Departure from Historical Variability

Multi-model averages showing the projected year of climate departure from historical variability for cities around the world using two Representative Concentration Pathway (RCP) scenarios. RCP4.5 represents a CO2 concentration of 538 ppm by 2100. RCP8.5 represents 936 ppm CO2 by  2100.

COUNTRY CITY

RCP8.5

RCP4.5

Afghanistan Kabul

2045

2071

Albania Tirana

2046

2070

Algeria Algiers

2041

2063

Andorra Andorra la Vella

2044

2070

Angola Luanda

2035

2052

Antigua and Barbuda St. John’s

2033

2047

Argentina Buenos Aires

2066

2094

Armenia Yerevan

2045

2076

Australia Perth

2042

2072

Australia Canberra

2045

2072

Australia Sydney

2038

2052

Australia Melbourne

2045

2073

Australia Brisbane

2042

2070

Austria Vienna

2055

2084

Azerbaijan Baku

2047

2072

Bahamas Nassau

2029

2041

Bahrain Manama

2032

2054

Bangladesh Dhaka

2054

2082

Barbados Bridgetown

2034

2046

Belarus Minsk

2065

2091

Belgium Brussels

2056

2086

Belize Belmopan

2034

2048

Benin Porto-Novo

2029

2043

Bhutan Thimphu

2035

2052

Bolivia La Paz

2028

2037

Bosnia and Herzegovina Sarajevo

2051

2079

Botswana Gaborone

2050

2083

Brazil Rio de Janeiro

2050

2079

Brazil São Paulo

2051

2083

Brazil Brasília

2047

2072

Brunei Bandar Seri Begawan

2027

2035

Bulgaria Sofia

2051

2082

Burkina Faso Ouagadougou

2036

2053

Burundi Bujumbura

2035

2049

Cambodia Phnom Penh

2043

2068

Cameroon Yaoundé

2025

2032

Canada Ottawa

2047

2072

Canada Toronto

2049

2074

Canada Montreal

2046

2072

Canada Vancouver

2056

2083

Cape Verde Praia

2042

2066

Central African Republic Bangui

2028

2036

Chad N’Djamena

2045

2075

Chile Santiago

2043

2071

China Beijing

2046

2078

China Shanghai

2045

2070

China Tianjin

2050

2080

China Guangzhou

2046

2072

China Shenzhen

2043

2065

China Dongguan

2044

2071

China Hong Kong

2043

2065

China Wuhan

2045

2070

China Chongqing

2046

2075

China Shenyang

2048

2080

Colombia Bogotá

2033

2047

Comoros Moroni

2031

2048

Costa Rica San José

2037

2058

Cote d’Ivoire Abidjan

2026

2034

Cote d’Ivoire Abidjan

2026

2034

Croatia Zagreb

2053

2085

Cuba Havana

2031

2045

Cyprus Nicosia

2039

2059

Czech Republic Prague

2056

2085

Denmark Copenhagen

2060

2089

Djibouti Djibouti

2034

2048

Dominica Roseau

2034

2048

Dominican Republic Santo Domingo

2026

2033

DR Congo Kinshasa

2028

2038

Ecuador Quito

2034

2050

Egypt Cairo

2036

2057

Egypt Alexandria

2036

2054

El Salvador San Salvador

2033

2049

Equatorial Guinea Malabo

2024

2030

Eritrea Asmara

2035

2053

Estonia Tallinn

2065

2091

Ethiopia Addis Ababa

2036

2054

Fiji Suva

2038

2065

Finland Helsinki

2063

2091

France Paris

2054

2084

Gabon Libreville

2024

2028

Georgia Tbilisi

2046

2077

Germany Berlin

2061

2090

Ghana Accra

2027

2034

Greece Athens

2041

2064

Grenada St. George’s

2032

2042

Guatemala Guatemala City

2038

2054

Guinea Conakry

2027

2036

Guinea-Bissau Bissau

2032

2045

Guyana Georgetown

2029

2039

Haiti Port-au-Prince

2025

2030

Honduras Tegucigalpa

2040

2055

Hungary Budapest

2056

2085

Iceland Reykjavik

2066

2084

India Mumbai

2034

2051

India Delhi

2050

2081

India Bangalore

2046

2069

India Hyderabad

2057

2085

India Ahmedabad

2046

2075

India Chennai

2034

2052

India Kolkata

2053

2081

India Surat

2045

2066

India Pune

2037

2055

India Jaipur

2045

2074

India New Delhi

2050

2081

Indonesia Jakarta

2029

2042

Indonesia Manokwari

2020

2025

Iran Tehran

2045

2068

Iraq Baghdad

2036

2055

Ireland Dublin

2059

2083

Israel Jerusalem

2038

2061

Italy Rome

2044

2067

Italy Milan

2048

2073

Italy Naples

2044

2065

Jamaica Kingston

2023

2028

Japan Tokyo

2041

2067

Japan Yokohama

2041

2067

Japan Kyoto

2040

2065

Jordan Amman

2040

2063

Kazakhstan Astana

2058

2091

Kazakhstan Almaty

2047

2075

Kenya Nairobi

2036

2058

Kiribati Tarawa

2049

2074

Kuwait Kuwait City

2036

2054

Kyrgyzstan Bishkek

2048

2077

Laos Vientiane

2056

2085

Latvia Riga

2064

2091

Lebanon Beirut

2040

2063

Lesotho Maseru

2038

2057

Liberia Monrovia

2025

2032

Libya Tripoli

2038

2059

Liechtenstein Vaduz

2051

2076

Lithuania Vilnius

2067

2091

Luxembourg Luxembourg City

2056

2083

Macedonia Skopje

2049

2080

Madagascar Antananarivo

2032

2047

Malawi Lilongwe

2036

2053

Malaysia Kuala Lumpur

2029

2039

Maldives Malé

2025

2027

Mali Bamako

2034

2051

Malta Valletta

2038

2054

Marshall Islands Majuro

2027

2036

Mauritania Nouakchott

2040

2069

Mauritius Port Louis

2037

2059

Mexico Mexico City

2031

2050

Micronesia Palikir

2024

2031

Moldova Chisinau

2058

2092

Monaco Monaco

2044

2066

Mongolia Ulan Bator

2054

2087

Montenegro Podgorica

2048

2075

Morocco Casablanca

2048

2080

Morocco Rabat

2046

2076

Mozambique Maputo

2038

2060

Myanmar Yangon

2036

2055

Myanmar Mandalay

2045

2072

Myanmar Yangon

2036

2055

Myanmar Naypyidaw

2041

2069

Namibia Windhoek

2044

2067

Nepal Kathmandu

2041

2063

Netherlands Amsterdam

2058

2086

New Zealand Wellington

2041

2070

Nicaragua Managua

2037

2052

Niger Niamey

2039

2060

Nigeria Lagos

2029

2043

Nigeria Abuja

2034

2047

North Korea Pyongyang

2042

2068

Norway Oslo

2061

2088

Oman Muscat

2032

2049

Pakistan Karachi

2035

2055

Pakistan Lahore

2049

2073

Pakistan Islamabad

2042

2064

Palau Ngerulmud

2023

2025

Panama Panama City

2031

2045

Papua New Guinea Port Moresby

2033

2043

Paraguay Asunción

2059

2086

Peru Lima

2038

2057

Peru Lima

2038

2057

Philippines Manila

2038

2055

Poland Warsaw

2063

2090

Portugal Lisbon

2052

2084

Qatar Doha

2033

2052

Republic of the Congo Brazzaville

2028

2038

Romania Bucharest

2054

2085

Russia Moscow

2063

2092

Russia Saint Petersburg

2064

2093

Rwanda Kigali

2031

2042

Saint Kitts and Nevis Basseterre

2033

2047

Saint Lucia Castries

2034

2047

Saint Vincent and the   Grenadines Kingstown

2033

2046

Samoa Apia

2028

2039

San Marino San Marino

2047

2072

Sao Tome and Principe São Tomé

2025

2028

Saudi Arabia Riyadh

2032

2050

Saudi Arabia Jeddah

2034

2050

Senegal Dakar

2044

2073

Serbia Belgrade

2054

2081

Seychelles Victoria

2027

2039

Sierra Leone Freetown

2028

2037

Singapore Singapore

2028

2037

Slovakia Bratislava

2055

2082

Slovenia Ljubljana

2051

2075

Solomon Islands Honiara

2024

2026

Somalia Mogadishu

2030

2040

South Africa Pretoria

2043

2068

South Africa Johannesburg

2043

2068

South Africa Cape Town

2038

2060

South Africa Durban

2035

2053

South Africa Bloemfontein

2043

2067

South Korea Seoul

2042

2067

South Korea Busan

2044

2068

South Sudan Juba

2041

2056

Spain Madrid

2046

2076

Spain Barcelona

2043

2065

Sri Lanka Colombo

2029

2037

Sudan Khartoum

2038

2062

Suriname Paramaribo

2028

2040

Swaziland Mbabane

2041

2067

Sweden Stockholm

2060

2089

Switzerland Bern

2050

2080

Switzerland Zurich

2050

2077

Switzerland Geneva

2048

2076

Syria Damascus

2041

2068

Taiwan Taipei

2042

2066

Tajikistan Dushanbe

2045

2071

Tanzania Dodoma

2040

2063

Tanzania Dar es Salaam

2034

2053

Thailand Bangkok

2046

2070

The Gambia Banjul

2037

2062

Timor-Leste Dili

2030

2040

Togo Lomé

2031

2046

Tonga Nukualofa

2043

2075

Trinidad and Tobago Port of Spain

2032

2044

Tunisia Tunis

2038

2060

Turkey Istanbul

2046

2075

Turkey Ankara

2047

2080

Turkmenistan Ashgabat

2046

2072

Tuvalu Funafuti

2029

2040

Uganda Kampala

2047

2064

UK London

2056

2088

Ukraine Kiev

2063

2090

United Arab Emirates Abu Dhabi

2033

2047

Uruguay Montevideo

2056

2084

USA Orlando

2046

2074

USA New York City

2047

2072

USA Washington DC

2047

2071

USA San Francisco

2049

2074

USA Anchorage

2071

2095

USA Honolulu

2043

2067

USA Los Angeles

2048

2079

USA Chicago

2052

2081

USA Houston

2050

2081

USA Philadelphia

2047

2072

USA Phoenix

2043

2073

USA San Diego

2046

2075

USA Dallas

2063

2093

USA Austin

2058

2090

USA Detroit

2051

2076

USA Seattle

2055

2082

USA Denver

2048

2079

Uzbekistan Tashkent

2046

2072

Vanuatu Port Vila

2038

2065

Venezuela Caracas

2034

2052

Vietnam Ho Chi Minh City

2039

2062

Vietnam Hanoi

2055

2085

Yemen Sanaa

2039

2060

Zambia Lusaka

2041

2067

Zimbabwe Harare

2044

2070