Population per country json (2 char ISO codes), parsed from http://download.geonames.org/export/dump/countryInfo.txt

iso2_population.json

{
  "AD": "84000",
  "AE": "4975593",
  "AF": "29121286",
  "AG": "86754",
  "AI": "13254",
  "AL": "2986952",
  "AM": "2968000",
  "AN": "300000",
  "AO": "13068161",
  "AQ": "0",
  "AR": "41343201",
  "AS": "57881",
  "AT": "8205000",
  "AU": "21515754",
  "AW": "71566",
  "AX": "26711",
  "AZ": "8303512",
  "BA": "4590000",
  "BB": "285653",
  "BD": "156118464",
  "BE": "10403000",
  "BF": "16241811",
  "BG": "7148785",
  "BH": "738004",
  "BI": "9863117",
  "BJ": "9056010",
  "BL": "8450",
  "BM": "65365",
  "BN": "395027",
  "BO": "9947418",
  "BQ": "18012",
  "BR": "201103330",
  "BS": "301790",
  "BT": "699847",
  "BV": "0",
  "BW": "2029307",
  "BY": "9685000",
  "BZ": "314522",
  "CA": "33679000",
  "CC": "628",
  "CD": "70916439",
  "CF": "4844927",
  "CG": "3039126",
  "CH": "7581000",
  "CI": "21058798",
  "CK": "21388",
  "CL": "16746491",
  "CM": "19294149",
  "CN": "1330044000",
  "CO": "47790000",
  "CR": "4516220",
  "CS": "10829175",
  "CU": "11423000",
  "CV": "508659",
  "CW": "141766",
  "CX": "1500",
  "CY": "1102677",
  "CZ": "10476000",
  "DE": "81802257",
  "DJ": "740528",
  "DK": "5484000",
  "DM": "72813",
  "DO": "9823821",
  "DZ": "34586184",
  "EC": "14790608",
  "EE": "1291170",
  "EG": "80471869",
  "EH": "273008",
  "ER": "5792984",
  "ES": "46505963",
  "ET": "88013491",
  "FI": "5244000",
  "FJ": "875983",
  "FK": "2638",
  "FM": "107708",
  "FO": "48228",
  "FR": "64768389",
  "GA": "1545255",
  "GB": "62348447",
  "GD": "107818",
  "GE": "4630000",
  "GF": "195506",
  "GG": "65228",
  "GH": "24339838",
  "GI": "27884",
  "GL": "56375",
  "GM": "1593256",
  "GN": "10324025",
  "GP": "443000",
  "GQ": "1014999",
  "GR": "11000000",
  "GS": "30",
  "GT": "13550440",
  "GU": "159358",
  "GW": "1565126",
  "GY": "748486",
  "HK": "6898686",
  "HM": "0",
  "HN": "7989415",
  "HR": "4284889",
  "HT": "9648924",
  "HU": "9982000",
  "ID": "242968342",
  "IE": "4622917",
  "IL": "7353985",
  "IM": "75049",
  "IN": "1173108018",
  "IO": "4000",
  "IQ": "29671605",
  "IR": "76923300",
  "IS": "308910",
  "IT": "60340328",
  "JE": "90812",
  "JM": "2847232",
  "JO": "6407085",
  "JP": "127288000",
  "KE": "40046566",
  "KG": "5776500",
  "KH": "14453680",
  "KI": "92533",
  "KM": "773407",
  "KN": "51134",
  "KP": "22912177",
  "KR": "48422644",
  "KW": "2789132",
  "KY": "44270",
  "KZ": "15340000",
  "LA": "6368162",
  "LB": "4125247",
  "LC": "160922",
  "LI": "35000",
  "LK": "21513990",
  "LR": "3685076",
  "LS": "1919552",
  "LT": "2944459",
  "LU": "497538",
  "LV": "2217969",
  "LY": "6461454",
  "MA": "33848242",
  "MC": "32965",
  "MD": "4324000",
  "ME": "666730",
  "MF": "35925",
  "MG": "21281844",
  "MH": "65859",
  "MK": "2062294",
  "ML": "13796354",
  "MM": "53414374",
  "MN": "3086918",
  "MO": "449198",
  "MP": "53883",
  "MQ": "432900",
  "MR": "3205060",
  "MS": "9341",
  "MT": "403000",
  "MU": "1294104",
  "MV": "395650",
  "MW": "15447500",
  "MX": "112468855",
  "MY": "28274729",
  "MZ": "22061451",
  "NA": "2128471",
  "NC": "216494",
  "NE": "15878271",
  "NF": "1828",
  "NG": "154000000",
  "NI": "5995928",
  "NL": "16645000",
  "NO": "5009150",
  "NP": "28951852",
  "NR": "10065",
  "NU": "2166",
  "NZ": "4252277",
  "OM": "2967717",
  "PA": "3410676",
  "PE": "29907003",
  "PF": "270485",
  "PG": "6064515",
  "PH": "99900177",
  "PK": "184404791",
  "PL": "38500000",
  "PM": "7012",
  "PN": "46",
  "PR": "3916632",
  "PS": "3800000",
  "PT": "10676000",
  "PW": "19907",
  "PY": "6375830",
  "QA": "840926",
  "RE": "776948",
  "RO": "21959278",
  "RS": "7344847",
  "RU": "140702000",
  "RW": "11055976",
  "SA": "25731776",
  "SB": "559198",
  "SC": "88340",
  "SD": "35000000",
  "SE": "9828655",
  "SG": "4701069",
  "SH": "7460",
  "SI": "2007000",
  "SJ": "2550",
  "SK": "5455000",
  "SL": "5245695",
  "SM": "31477",
  "SN": "12323252",
  "SO": "10112453",
  "SR": "492829",
  "SS": "8260490",
  "ST": "175808",
  "SV": "6052064",
  "SX": "37429",
  "SY": "22198110",
  "SZ": "1354051",
  "TC": "20556",
  "TD": "10543464",
  "TF": "140",
  "TG": "6587239",
  "TH": "67089500",
  "TJ": "7487489",
  "TK": "1466",
  "TL": "1154625",
  "TM": "4940916",
  "TN": "10589025",
  "TO": "122580",
  "TR": "77804122",
  "TT": "1228691",
  "TV": "10472",
  "TW": "22894384",
  "TZ": "41892895",
  "UA": "45415596",
  "UG": "33398682",
  "UM": "0",
  "US": "310232863",
  "UY": "3477000",
  "UZ": "27865738",
  "VA": "921",
  "VC": "104217",
  "VE": "27223228",
  "VG": "21730",
  "VI": "108708",
  "VN": "89571130",
  "VU": "221552",
  "WF": "16025",
  "WS": "192001",
  "XK": "1800000",
  "YE": "23495361",
  "YT": "159042",
  "ZA": "49000000",
  "ZM": "13460305",
  "ZW": "13061000"
}

Do you still have the script to update this? (Although at closer look it looks like the source hasn't been updated either :( )